We have 2 new iphone 13 pros trying to use the same apple id. Is this possible? One is working and the other keeps going back to factory reset during setup

While it is possible to use the same Apple ID on two phones, it is not a good idea if the phones are going to be used by 2 different people. Each individual should have their own Apple ID. Hard to say if something is wrong with the phone you are experiencing a problem with, but you should start over again and create a new Apple ID for that device and then activate it.