Dialogs open then close/disappear very quickly (Anki Version 2.1.35)

When I click Sync, the account details window appears and then disappears (very quickly).

Similarly, when I click ‘Rename’ in Switch Profiles, the dialog rolls down and then up again immediately (appearing and disappearing). The Switch Profiles dialog itself displays okay, ie. it seems to be more the “popup” windows that do this.

Anki flashcards still work (ie. the main dialog is okay)

I’m happy to run in a diagnostic mode or post diagnostic/error log files if you can point me to them.

Starting with shift held down doesn’t seem to make any difference to this issue.

thanks for any pointers!

Please see https://faqs.ankiweb.net/when-problems-occur.html

I did - and I did all of the steps except for the reboot.
And that, it turns out, is what was needed to fix it!

thanks Dae!