diff --git a/x-pack/plugins/triggers_actions_ui/public/application/components/builtin_action_types/email/email_params.test.tsx b/x-pack/plugins/triggers_actions_ui/public/application/components/builtin_action_types/email/email_params.test.tsx
index 3cd54b58bf29a..6ead65d958bd5 100644
--- a/x-pack/plugins/triggers_actions_ui/public/application/components/builtin_action_types/email/email_params.test.tsx
+++ b/x-pack/plugins/triggers_actions_ui/public/application/components/builtin_action_types/email/email_params.test.tsx
@@ -33,4 +33,97 @@ describe('EmailParamsFields renders', () => {
     expect(wrapper.find('[data-test-subj="subjectInput"]').length > 0).toBeTruthy();
     expect(wrapper.find('[data-test-subj="messageTextArea"]').length > 0).toBeTruthy();
   });
+
+  test('message param field is rendered with default value if not set', () => {
+    const actionParams = {
+      cc: [],
+      bcc: [],
+      to: ['test@test.com'],
+      subject: 'test',
+    };
+
+    const editAction = jest.fn();
+    mountWithIntl(
+      <EmailParamsFields
+        actionParams={actionParams}
+        errors={{ to: [], cc: [], bcc: [], subject: [], message: [] }}
+        editAction={editAction}
+        defaultMessage={'Some default message'}
+        index={0}
+      />
+    );
+
+    expect(editAction).toHaveBeenCalledWith('message', 'Some default message', 0);
+  });
+
+  test('when the default message changes, so is the underlying message if it was set by the previous default', () => {
+    const actionParams = {
+      cc: [],
+      bcc: [],
+      to: ['test@test.com'],
+      subject: 'test',
+    };
+
+    const editAction = jest.fn();
+    const wrapper = mountWithIntl(
+      <EmailParamsFields
+        actionParams={actionParams}
+        errors={{ to: [], cc: [], bcc: [], subject: [], message: [] }}
+        editAction={editAction}
+        defaultMessage={'Some default message'}
+        index={0}
+      />
+    );
+
+    expect(editAction).toHaveBeenCalledWith('message', 'Some default message', 0);
+
+    wrapper.setProps({
+      defaultMessage: 'Some different default message',
+    });
+
+    expect(editAction).toHaveBeenCalledWith('message', 'Some different default message', 0);
+  });
+
+  test('when the default message changes, it doesnt change the underlying message if it wasnt set by a previous default', () => {
+    const actionParams = {
+      cc: [],
+      bcc: [],
+      to: ['test@test.com'],
+      subject: 'test',
+    };
+
+    const editAction = jest.fn();
+    const wrapper = mountWithIntl(
+      <EmailParamsFields
+        actionParams={actionParams}
+        errors={{ to: [], cc: [], bcc: [], subject: [], message: [] }}
+        editAction={editAction}
+        defaultMessage={'Some default message'}
+        index={0}
+      />
+    );
+
+    expect(editAction).toHaveBeenCalledWith('message', 'Some default message', 0);
+
+    // simulate value being updated
+    const valueToSimulate = 'some new value';
+    wrapper
+      .find('[data-test-subj="messageTextArea"]')
+      .first()
+      .simulate('change', { target: { value: valueToSimulate } });
+    expect(editAction).toHaveBeenCalledWith('message', valueToSimulate, 0);
+    wrapper.setProps({
+      actionParams: {
+        ...actionParams,
+        message: valueToSimulate,
+      },
+    });
+
+    // simulate default changing
+    wrapper.setProps({
+      defaultMessage: 'Some different default message',
+    });
+
+    expect(editAction).not.toHaveBeenCalledWith('message', 'Some different default message', 0);
+  });
 });
diff --git a/x-pack/plugins/triggers_actions_ui/public/application/components/builtin_action_types/email/email_params.tsx b/x-pack/plugins/triggers_actions_ui/public/application/components/builtin_action_types/email/email_params.tsx
index eacdf20747fdc..1030ce34d2569 100644
--- a/x-pack/plugins/triggers_actions_ui/public/application/components/builtin_action_types/email/email_params.tsx
+++ b/x-pack/plugins/triggers_actions_ui/public/application/components/builtin_action_types/email/email_params.tsx
@@ -11,7 +11,6 @@ import { ActionParamsProps } from '../../../../types';
 import { EmailActionParams } from '../types';
 import { TextFieldWithMessageVariables } from '../../text_field_with_message_variables';
 import { TextAreaWithMessageVariables } from '../../text_area_with_message_variables';
-import { resolvedActionGroupMessage } from '../../../constants';
 
 export const EmailParamsFields = ({
   actionParams,
@@ -28,17 +27,19 @@ export const EmailParamsFields = ({
   const [addCC, setAddCC] = useState<boolean>(false);
   const [addBCC, setAddBCC] = useState<boolean>(false);
 
+  const [[isUsingDefault, defaultMessageUsed], setDefaultMessageUsage] = useState<
+    [boolean, string | undefined]
+  >([false, defaultMessage]);
   useEffect(() => {
-    if (defaultMessage === resolvedActionGroupMessage) {
-      editAction('message', defaultMessage, index);
-    } else if (
-      (!message || message === resolvedActionGroupMessage) &&
-      defaultMessage &&
-      defaultMessage.length > 0
+    if (
+      !actionParams?.message ||
+      (isUsingDefault &&
+        actionParams?.message === defaultMessageUsed &&
+        defaultMessageUsed !== defaultMessage)
     ) {
+      setDefaultMessageUsage([true, defaultMessage]);
       editAction('message', defaultMessage, index);
     }
-
     // eslint-disable-next-line react-hooks/exhaustive-deps
   }, [defaultMessage]);
 
diff --git a/x-pack/plugins/triggers_actions_ui/public/application/components/builtin_action_types/jira/search_issues.tsx b/x-pack/plugins/triggers_actions_ui/public/application/components/builtin_action_types/jira/search_issues.tsx
index fff606982677a..8a98a9eb7bb75 100644
--- a/x-pack/plugins/triggers_actions_ui/public/application/components/builtin_action_types/jira/search_issues.tsx
+++ b/x-pack/plugins/triggers_actions_ui/public/application/components/builtin_action_types/jira/search_issues.tsx
@@ -14,7 +14,7 @@ import { useGetSingleIssue } from './use_get_single_issue';
 import * as i18n from './translations';
 
 interface Props {
-  selectedValue: string | null;
+  selectedValue?: string | null;
   http: HttpSetup;
   toastNotifications: Pick<
     ToastsApi,
diff --git a/x-pack/plugins/triggers_actions_ui/public/application/components/builtin_action_types/jira/use_get_fields_by_issue_type.tsx b/x-pack/plugins/triggers_actions_ui/public/application/components/builtin_action_types/jira/use_get_fields_by_issue_type.tsx
index 8685ee1e615b0..6129f42923e45 100644
--- a/x-pack/plugins/triggers_actions_ui/public/application/components/builtin_action_types/jira/use_get_fields_by_issue_type.tsx
+++ b/x-pack/plugins/triggers_actions_ui/public/application/components/builtin_action_types/jira/use_get_fields_by_issue_type.tsx
@@ -23,7 +23,7 @@ interface Props {
     ToastsApi,
     'get$' | 'add' | 'remove' | 'addSuccess' | 'addWarning' | 'addDanger' | 'addError'
   >;
-  issueType: string;
+  issueType: string | undefined;
   actionConnector?: ActionConnector;
 }
 
diff --git a/x-pack/plugins/triggers_actions_ui/public/application/components/builtin_action_types/jira/use_get_single_issue.tsx b/x-pack/plugins/triggers_actions_ui/public/application/components/builtin_action_types/jira/use_get_single_issue.tsx
index c0d2eae14bead..85fc94733e8a8 100644
--- a/x-pack/plugins/triggers_actions_ui/public/application/components/builtin_action_types/jira/use_get_single_issue.tsx
+++ b/x-pack/plugins/triggers_actions_ui/public/application/components/builtin_action_types/jira/use_get_single_issue.tsx
@@ -22,7 +22,7 @@ interface Props {
     ToastsApi,
     'get$' | 'add' | 'remove' | 'addSuccess' | 'addWarning' | 'addDanger' | 'addError'
   >;
-  id: string | null;
+  id?: string | null;
   actionConnector?: ActionConnector;
 }
 
diff --git a/x-pack/plugins/triggers_actions_ui/public/application/components/builtin_action_types/server_log/server_log_params.test.tsx b/x-pack/plugins/triggers_actions_ui/public/application/components/builtin_action_types/server_log/server_log_params.test.tsx
index 0552a126ca66f..86dd304bf6b12 100644
--- a/x-pack/plugins/triggers_actions_ui/public/application/components/builtin_action_types/server_log/server_log_params.test.tsx
+++ b/x-pack/plugins/triggers_actions_ui/public/application/components/builtin_action_types/server_log/server_log_params.test.tsx
@@ -9,8 +9,8 @@ import { ServerLogLevelOptions } from '.././types';
 import ServerLogParamsFields from './server_log_params';
 
 describe('ServerLogParamsFields renders', () => {
-  const editAction = jest.fn();
   test('all params fields is rendered', () => {
+    const editAction = jest.fn();
     const actionParams = {
       level: ServerLogLevelOptions.TRACE,
       message: 'test',
@@ -35,20 +35,103 @@ describe('ServerLogParamsFields renders', () => {
   test('level param field is rendered with default value if not selected', () => {
     const actionParams = {
       message: 'test message',
-      level: ServerLogLevelOptions.INFO,
     };
+    const editAction = jest.fn();
+
+    mountWithIntl(
+      <ServerLogParamsFields
+        actionParams={actionParams}
+        errors={{ message: [] }}
+        editAction={editAction}
+        index={0}
+      />
+    );
+
+    expect(editAction).toHaveBeenCalledWith('level', 'info', 0);
+  });
+
+  test('message param field is rendered with default value if not set', () => {
+    const actionParams = {
+      level: ServerLogLevelOptions.TRACE,
+    };
+
+    const editAction = jest.fn();
+
+    mountWithIntl(
+      <ServerLogParamsFields
+        actionParams={actionParams}
+        defaultMessage={'Some default message'}
+        errors={{ message: [] }}
+        editAction={editAction}
+        index={0}
+      />
+    );
+
+    expect(editAction).toHaveBeenCalledWith('message', 'Some default message', 0);
+  });
+
+  test('when the default message changes, so is the underlying message if it was set by the previous default', () => {
+    const actionParams = {
+      level: ServerLogLevelOptions.TRACE,
+    };
+
+    const editAction = jest.fn();
     const wrapper = mountWithIntl(
       <ServerLogParamsFields
         actionParams={actionParams}
+        defaultMessage={'Some default message'}
         errors={{ message: [] }}
-        editAction={() => {}}
+        editAction={editAction}
         index={0}
       />
     );
-    expect(wrapper.find('[data-test-subj="loggingLevelSelect"]').length > 0).toBeTruthy();
-    expect(
-      wrapper.find('[data-test-subj="loggingLevelSelect"]').first().prop('value')
-    ).toStrictEqual('info');
-    expect(wrapper.find('[data-test-subj="messageTextArea"]').length > 0).toBeTruthy();
+
+    expect(editAction).toHaveBeenCalledWith('message', 'Some default message', 0);
+
+    wrapper.setProps({
+      defaultMessage: 'Some different default message',
+    });
+
+    expect(editAction).toHaveBeenCalledWith('message', 'Some different default message', 0);
+  });
+
+  test('when the default message changes, it doesnt change the underlying message if it wasnt set by a previous default', () => {
+    const actionParams = {
+      level: ServerLogLevelOptions.TRACE,
+    };
+
+    const editAction = jest.fn();
+    const wrapper = mountWithIntl(
+      <ServerLogParamsFields
+        actionParams={actionParams}
+        defaultMessage={'Some default message'}
+        errors={{ message: [] }}
+        editAction={editAction}
+        index={0}
+      />
+    );
+
+    expect(editAction).toHaveBeenCalledWith('message', 'Some default message', 0);
+
+    // simulate value being updated
+    const valueToSimulate = 'some new value';
+    wrapper
+      .find('[data-test-subj="messageTextArea"]')
+      .first()
+      .simulate('change', { target: { value: valueToSimulate } });
+    expect(editAction).toHaveBeenCalledWith('message', valueToSimulate, 0);
+    wrapper.setProps({
+      actionParams: {
+        ...actionParams,
+        message: valueToSimulate,
+      },
+    });
+
+    // simulate default changing
+    wrapper.setProps({
+      defaultMessage: 'Some different default message',
+    });
+
+    expect(editAction).not.toHaveBeenCalledWith('message', 'Some different default message', 0);
   });
 });
diff --git a/x-pack/plugins/triggers_actions_ui/public/application/components/builtin_action_types/server_log/server_log_params.tsx b/x-pack/plugins/triggers_actions_ui/public/application/components/builtin_action_types/server_log/server_log_params.tsx
index e8c427371c4a5..ce426c72b64b4 100644
--- a/x-pack/plugins/triggers_actions_ui/public/application/components/builtin_action_types/server_log/server_log_params.tsx
+++ b/x-pack/plugins/triggers_actions_ui/public/application/components/builtin_action_types/server_log/server_log_params.tsx
@@ -3,13 +3,12 @@
  * or more contributor license agreements. Licensed under the Elastic License;
  * you may not use this file except in compliance with the Elastic License.
  */
-import React, { Fragment, useEffect } from 'react';
+import React, { Fragment, useEffect, useState } from 'react';
 import { i18n } from '@kbn/i18n';
 import { EuiSelect, EuiFormRow } from '@elastic/eui';
 import { ActionParamsProps } from '../../../../types';
 import { ServerLogActionParams } from '.././types';
 import { TextAreaWithMessageVariables } from '../../text_area_with_message_variables';
-import { resolvedActionGroupMessage } from '../../../constants';
 
 export const ServerLogParamsFields: React.FunctionComponent<
   ActionParamsProps<ServerLogActionParams>
@@ -23,25 +22,26 @@ export const ServerLogParamsFields: React.FunctionComponent<
     { value: 'error', text: 'Error' },
     { value: 'fatal', text: 'Fatal' },
   ];
-
   useEffect(() => {
-    if (!actionParams?.level) {
+    if (!actionParams.level) {
       editAction('level', 'info', index);
     }
     // eslint-disable-next-line react-hooks/exhaustive-deps
   }, []);
 
+  const [[isUsingDefault, defaultMessageUsed], setDefaultMessageUsage] = useState<
+    [boolean, string | undefined]
+  >([false, defaultMessage]);
   useEffect(() => {
-    if (defaultMessage === resolvedActionGroupMessage) {
-      editAction('message', defaultMessage, index);
-    } else if (
-      (!message || message === resolvedActionGroupMessage) &&
-      defaultMessage &&
-      defaultMessage.length > 0
+    if (
+      !actionParams?.message ||
+      (isUsingDefault &&
+        actionParams?.message === defaultMessageUsed &&
+        defaultMessageUsed !== defaultMessage)
     ) {
+      setDefaultMessageUsage([true, defaultMessage]);
       editAction('message', defaultMessage, index);
     }
-
     // eslint-disable-next-line react-hooks/exhaustive-deps
   }, [defaultMessage]);
 
diff --git a/x-pack/plugins/triggers_actions_ui/public/application/components/builtin_action_types/slack/slack_params.tsx b/x-pack/plugins/triggers_actions_ui/public/application/components/builtin_action_types/slack/slack_params.tsx
index d1498567218d3..40818c327af60 100644
--- a/x-pack/plugins/triggers_actions_ui/public/application/components/builtin_action_types/slack/slack_params.tsx
+++ b/x-pack/plugins/triggers_actions_ui/public/application/components/builtin_action_types/slack/slack_params.tsx
@@ -3,12 +3,11 @@
  * or more contributor license agreements. Licensed under the Elastic License;
  * you may not use this file except in compliance with the Elastic License.
  */
-import React, { useEffect } from 'react';
+import React, { useEffect, useState } from 'react';
 import { i18n } from '@kbn/i18n';
 import { ActionParamsProps } from '../../../../types';
 import { SlackActionParams } from '../types';
 import { TextAreaWithMessageVariables } from '../../text_area_with_message_variables';
-import { resolvedActionGroupMessage } from '../../../constants';
 
 const SlackParamsFields: React.FunctionComponent<ActionParamsProps<SlackActionParams>> = ({
   actionParams,
@@ -19,17 +18,19 @@ const SlackParamsFields: React.FunctionComponent<ActionParamsProps<SlackActionPa
   defaultMessage,
 }) => {
   const { message } = actionParams;
+  const [[isUsingDefault, defaultMessageUsed], setDefaultMessageUsage] = useState<
+    [boolean, string | undefined]
+  >([false, defaultMessage]);
   useEffect(() => {
-    if (defaultMessage === resolvedActionGroupMessage) {
-      editAction('message', defaultMessage, index);
-    } else if (
-      (!message || message === resolvedActionGroupMessage) &&
-      defaultMessage &&
-      defaultMessage.length > 0
+    if (
+      !actionParams?.message ||
+      (isUsingDefault &&
+        actionParams?.message === defaultMessageUsed &&
+        defaultMessageUsed !== defaultMessage)
     ) {
+      setDefaultMessageUsage([true, defaultMessage]);
       editAction('message', defaultMessage, index);
     }
-
     // eslint-disable-next-line react-hooks/exhaustive-deps
   }, [defaultMessage]);
 
diff --git a/x-pack/plugins/triggers_actions_ui/public/types.ts b/x-pack/plugins/triggers_actions_ui/public/types.ts
index be8b7b9757e9e..a4eac1ab1da21 100644
--- a/x-pack/plugins/triggers_actions_ui/public/types.ts
+++ b/x-pack/plugins/triggers_actions_ui/public/types.ts
@@ -48,7 +48,7 @@ export interface ActionConnectorFieldsProps<TActionConnector> {
 }
 
 export interface ActionParamsProps<TParams> {
-  actionParams: TParams;
+  actionParams: Partial<TParams>;
   index: number;
   editAction: (key: string, value: AlertActionParam, index: number) => void;
   errors: IErrorObject;