SIM PIM lock on iPhone Xr with parental controls after a screen change

Customer brought in his daughter's iPhone XR for a screen change. I tested all functions before beginning without any issues. After repair, the phone is SIM PIN locked. He says they never set a SIM PIN code, but they do have the phone set up with lots of parental controls. Can parental controls automatically create a SIM PIN or is that something the customer has to set up themselves? Also, though it has never happened to me before as long as I've been repairing phones, could I have done anything during repair which would automatically cause the SIM PIN to lock on its own? Thanks.