I had this issue too. I'm already on two-factor with Authenticator, so it wasn't a big deal. Since nothing had changed with my account, and the device history l

I had this issue too. I'm already on two-factor with Authenticator, so it wasn't a big deal. Since nothing had changed with my account, and the device history looked proper, I assumed it was a token expiration deal. Which is what it turns out to be. Good to know that was the problem.