I built a Chrome Extension using the Google Slides API ~8 months ago, with users having to sign in with the OAuth consent screen as to be able to use the extension. The extension has over a thousand users, and for the past weeks I've had reports of people seeing an error that says "Sign in with Google temporarily disabled for this app".
I checked and indeed the OAuth page was still "being verified", although it still said it would only take a few days / several weeks. I'm not using any sensitive scopes either, so it all seems very odd. If the app didn't meet the criteria I would have been rejected, but that doesn't seem to be the case.
So my question is, how can I get it verified, or if anything rejected so that I can make a new submission? I looked all over the place and I haven't found a way to get it unstuck. I'm pretty sure 8 months for verification isn't normal whatsoever.
Google seems to manually validate each OAuth screen. That's a long (and costly process), but to my experience, it generally takes 24 hours if you don't use any sensitive/restrictive scopes. As it's your case apparently, I presume your submission has probably being lost somewhere.
My recommendations:
Disclaimer: I don't work at Google. But I'm bit familiar with that process now :)