exisiting account

Hello everyone, I have bought a Xiaomi 13 ultra in china and as a student in IT, I knew it was possible to flash Eu version of it. So I have unlock the phone by creating a new account with my phone number on the phone. After unlocked it on the computer I have tried to flash with the official Eu...

There may already be a post on this, however I am unable to find it. My problem: I did a factory reset on my phone, however when i turn the phone back on and try to connect to the internet the phone suddenly blocks with the message: " This device may be associated with existing Mi account...