[Oauth] refresh token returns 401

Hi ,
I’ve noticed this issue has been covered a few times, but i dont think this use-case seems to fit.

I have an application that implements the Oauth integration with the Patreon API and
multiple Patreon creators have integrated with it.
The application receives the refresh and access tokens correctly and seems to work well with the Patreon API up until when trying to refresh the token.

Then, for some creators im able to refresh the token successfully and in some cases, i receive 401 - invalid_grant.
i followed the guidelines here - API Reference

I understand from a previous posts there is no limit on the amount of tokens registered with a single Client,
Is there any debug flag or added information i can get from the API ?
We try to refresh the token within 1-5min from the access token expiration date, is there some caveat with it ?

Any information will be be appreciated,
thanks tal.

This may be related to a bug reported with creator tokens auto-refreshing when the creator re-logs in to one’s application. (like yours). If you can try to see if that pattern exists by asking creators who encountered this problem (ie whether they recently logged into your app or Patreon before logging in), that may help.