setting up new iPhone - verification failed

Upgrading a user from iPhone 6s to iPhone 11. Tried various methods but would prefer to use the side-by-side method to move all data and settings over to new iPhone. Each time I try to setup the new Phone it gets as far as asking for the users PIN from the old iPhone before throwing up 'verification failed'. It detects when an incorrect PIN is entered but will not verify with the correct PIN.

Have restarted and wiped the new phone between each method of setup, including manual setup with a new appleID using a appleID given from the apple servers but it always fails verification!

I have also tried setting up the phone with a different appleID (my own) and it also fails verification when asking for my PIN for my current device

Took the new phone to local apple store but they had no ideas other than to ask on here