Revin ecu issues please help asap

I'm rewriting the vin on a 2016 regal. got used computer from donor car and when i put the vin in it saids i can commit. so i click it and write the configurations and the cycle ignition and then i check and it still shows old vin.. is there another place i have to change it besides in the vin wizard? never had this issue with any other car, trying to see if there is couple diff places to do it. please let me know asap, as i have the security thing on the dash since i disabled vats to get car running..