Rich text controls disappear when Yoast SEO activated

[bobbingwide]

I first noticed this problem while trying to use bold on a paragraph block in s.b/wordpress.
The Bold, Italic and More rich text controls toolicons are missing
The problem went away when I deactivated Yoast SEO 15.3 (screenshot 2) .
But I couldn't reproduce the problem in other environments.

Time to do some analysis to determine what's causing the problem

Environment	WordPress	Gutenberg	Yoast SEO	Other plugins	Working?
s.b/wordpress	5.5.1	9.4.0	15.3	many	No
s.b/wordpress	5.5.1	9.3.0	15.3	many	No

A message in the console when it doesn't work is:

react-dom.82e849f1.js:1680 Warning: Failed prop type: You provided a `value` prop to a form field without an `onChange` handler. This will render a read-only field. If the field should be mutable use `defaultValue`. Otherwise, set either `onChange` or `readOnly`.
    in select (created by y)
    in div (created by u)
...

[bobbingwide]

This doesn't happen anymore with Yoast SEO v15.7, not v15.8. Not sure which version resolved the problem.