Is this with config from text files or via UI?
While I prefer config by text files myself I found that refreshing the auth token seems to fail with config files. Google TTS is about the only thing I config via the UI for that reason.
That said, I still have to create a new auth code once or twice a week, oauth2.0 with Google is a fragile affair and all the irritating dialogs and warnngs on top of it - not for the faint of heart.