Hey Tiana. Sounds like something strange is going on, but I’m not aware of any generic issue with OAuth on our side at the moment (that’s not to say there isn’t one - just that I haven’t heard of one!)
The token limit is unlikely to be an issue here since it only applies to apps reproducing the Twitter client experience, and as you say, you’re probably not close to it. Checking on that requires sharing app-specific information like the App ID / name / access tokens so we can’t help with that via the forums (you can open a Platform Support ticket to ask for assistance).
There’s no different limit for “basic access” (I assume you mean read-only?) tokens vs any others. Again, the 100k limit is only applicable to a small category of apps that use the API. What kind of things is your app using the API for?
The only way I know of to revoke tokens from the perspective of an app developer is the somewhat “nuclear” option of regenerating app key and secret - which would have the effect of requiring all auth’d users to login again.