Another device using my account?

I just received this following the recent update. I’m aware that the servers are melting and things are being wacky for everyone, but I also want to make sure my account is safe. I haven’t logged into any other device with my account. I am hoping that this is simply a mistake but I have to be safe.

Your account is safe! You will back online once the issue has been resolved.

Known issue. Will be addressed shortly

This is a known technical issue at the moment and the developers are working as fast as possible to resolve it.

More information can be found here. Thank you for your understanding and your patience.