Base band problem

Wish to find out if resetting an iPhone 11 could cause base band problem?

because i was using an iPhone 11 over 9months now bought it sealed it had a cracked on the back but was functioning properly with no network issues.

i decided to swap the phone to iPhone 12 and the deal was done after some days the seller calls me saying after he resetting my iPhone 11 he notice the phone has a base band problem is that even possible because he want me to come and reverse the deal else he’ll block the iPhone 12 i bought from him.

Please need an answer urgently. Thanks.