Hello @Willyham!
Our team investigated trying to pass in params to let Google know that auth tokens should last longer than an hour but currently their API no longer accepts this param 
If you have selected Custom Auth and then chosen the OAuth 2.0 option, then the resource should refresh auth when the backend returns a 400 or when google auth fails.
Here is a link to another thread where my team member came up with a test to check and see if a new token is auto-generated correctly.
Check this out and see if the token is re-generated, if not there might be an issue with the resource set up. In this case, let me know and I can open a DM conversation with you to share a screenshot to further troubleshoot.