Registration error: PUK code is not accepted

Hello! I am trying to register my new SIM card on the Mein O2 website and in the mobile app. I have been successfully using the SIM card for a week already. However, during the registration process, after I enter the SMS confirmation code, the system asks for my PUK.

When I type it in, it throws an error saying the PUK is wrong (although it is 100% correct from the plastic card holder). I tried it about 5 times both on the website and in the app, but the error is the same.

Could a moderator please help me to update my profile data so I can finally access my personal account? Thank you!