Strange error with notes editor

Your software
My Mautic version is: 5.2.1

Your problem
My problem is:

In an instance, the editor for notes seem a bit off:

Too many tools and with missing icon.
Correctly it would look like this:

We already checked, that files are the same for two instances, where one is working and one not.
We isolated that the problem probably lies within the database.

Does anyone have a hint, where the configuration of the editor is handled in the database?
Any recommendations?

Thanks a lot!