Tasks not syncing in Evolution (Ubuntu 16.04 Evolution v3.18.5.2)

[zeigerpuppy]

Calendar Sync is working well in Evolution, but tasks don't sync.
The task app says that tasks should sync automatically when CalDAV calendar sync is enabled.

Steps to reproduce

1. set up CalDAV calendar sync in evolution
2. create Tasks locally and on Nextcloud Server
3. try to refresh

Expected behaviour

Tasks should sync

Actual behaviour

Tasks don't sync

Server configuration

Operating system:
Ubuntu 16.04

Web server:
nginx

Database:
MySQL (MariaDB)

PHP version:
7.1

Nextcloud version: (see Nextcloud admin page)
9.1.1

Updated from an older Nextcloud/ownCloud or fresh install:
no, fresh install

Where did you install Nextcloud from:
installer tarball

Login as admin user into your Nextcloud and access
http://example.com/index.php/settings/integrity/failed
paste the results here.

No errors have been found.

If you have access to your command line run e.g.:
sudo -u www-data php occ app:list
from within your Nextcloud installation folder

Enabled:
  - activity: 2.3.2
  - bookmarks: 0.9.0
  - calendar: 1.4.1
  - comments: 1.0.0
  - contacts: 1.5.1
  - dav: 1.0.0
  - documents: 0.13.1
  - external: true
  - federatedfilesharing: 1.0.1
  - federation: 1.0.1
  - files: 1.5.2
  - files_pdfviewer: 0.8.1
  - files_sharing: 1.0.0
  - files_texteditor: 2.1
  - files_trashbin: 1.0.0
  - files_versions: 1.3.0
  - files_videoplayer: 0.9.8
  - firstrunwizard: 1.1
  - gallery: 15.0.0
  - notifications: 0.3.0
  - password_policy: 1.0.0
  - provisioning_api: 1.0.0
  - serverinfo: 1.1.1
  - survey_client: 0.1.5
  - systemtags: 1.0.2
  - tasks: 0.9.4
  - theming: 1.0.1
  - updatenotification: 1.0.1
  - user_external: 0.4
  - workflowengine: 1.0.1
Disabled:
  - admin_audit
  - encryption
  - files_accesscontrol
  - files_automatedtagging
  - files_external
  - files_retention
  - mail
  - ojsxc
  - ownnote
  - templateeditor
  - user_ldap
  - user_saml

Are you using external storage, if yes which one: local/smb/sftp/...
No

Are you using encryption: yes/no
No

Are you using an external user-backend, if yes which one: LDAP/ActiveDirectory/Webdav/...
Yes, IMAP

Client configuration

Browser:
Evolution v3.18.5.2

Operating system:
16.04

Logs

Web server error log

Web server error log

``` no errors ```

Nextcloud log (data/nextcloud.log)

Nextcloud log

``` no errors on sync ```

[jancborchardt]

Any idea here @nextcloud/tasks @nextcloud/calendar? :)

[tcitworld]

Hmm, just tested and it works for me by adding my account through the Gnome Online Accounts.

I'm using Gnome (and Evolution) 3.22.6 though, so it may be related to your Gnome version.
By the way, you should also update your Nextcloud version.