I got this message today aswell, for the first time.
I'm in EU and on enforced WireGuard, EU server.
I am using Quad9 DNS via TLS aswell. Can it be that it reacts as switching US/EU depending on DNS relay location (which is EU on lookup but who knows) ?
Edit: I do have Orbot installed but I have never used it and it has never been activated. I have just been looking around. And Location is turned off.