This happened to me recently and I have never seen it before. I was wondering what caused this and if this is common.
I have logged into all my accounts, so I do not remember the exact phrasing of the messages and, therefore, I could not find the exact error message.
I did not disconnect anywhere else (for example, the gmail tabs of my computer)
I'm on Android P if that matters. The last time I updated my phone was a week ago, so I think it should not have had any effect on things.