Visual mode not working

For writing my posts I use the Classic Editor, and have TinyMCE Advanced installed. Working the old way, so, not the block editor.
Writing in the editor field does not work when the visual mode is on. Only after switching to the text mode I can write.
In visual mode there’s no cursor.
After having written a post in the text mode (and saved it), switching to visual mode gives an empty window, the saved post is not there.

After disabling this plugin, the visual mode of the editor can be used again.
What could cause the problem and how can it be solved?

• This topic was modified 3 years, 11 months ago by gunivortus01.
• This topic was modified 3 years, 11 months ago by gunivortus01.

The page I need help with: [log in to see the link]