In my case I'm using Linux Mint 19.2 Cinnamon. I have only this problem as soon as I enable the extension LanguageTool and try to insert a formula into writer. If I disable LanguageTool, then the problem is gone.
I filed the bug as https://bugs.documentfoundation.org/show_bug.cgi?id=128491 which might be a duplicate of this bug. Today I managed to duplicate the menu as much as I wanted (see attachment)
In my case I'm using Linux Mint 19.2 Cinnamon. I have only this problem as soon as I enable the extension LanguageTool and try to insert a formula into writer. If I disable LanguageTool, then the problem is gone.
I filed the bug as https:/ /bugs.documentf oundation. org/show_ bug.cgi? id=128491 which might be a duplicate of this bug. Today I managed to duplicate the menu as much as I wanted (see attachment)