Started happening a few days back and it is extremely frustrating. I use this site daily and of course there are credentials for it. Regardless, I re-saved them, updated them and whatever else. No change.
I moved your post out of this feature request, as it seems like an autofill issue and should rather be in the “Ask the Community” section.
(your issue probably could be solved if it was possible when you could deactivate the inline generator – but on a site with existing credentials, you shouldn’t even see the generator)
You can still add your voice and vote (the latter one when you reach the next forum trust level) to that feature request.
PS: Ah, and the official links to report autofill issues: