First of all, I didn’t log into any new device. I recently changed the password of this account and do not have it stored anywhere. It is also a new google account that hasn’t been shared anywhere but with the services.
Today, I received a Google verification code from the usual number. Two minutes later I received one from a local German number that seems to be unaffiliated with Google – however – the code was the exact same.
See here: [https://imgur.com/a/pBOZhzt](https://imgur.com/a/pBOZhzt)