NR7101 doesn't see simcard

I recently bought a secondhand NR7101 (doing my bit for the planet!) for my parents but it does not detect the sim. I have another NR7101 (possibly a different version, who knows) and that works fine. After updating both to NR7101_1.16(ACCC.1)C0 and factory resetting (one working, one not) I looked through and noticed that one had no info under "DFOTA Upgrade Current LTE Module Version:" the one working had RG502QEAAAR11A03M4G. Does this mean the LTE module needs to be updated? If so where do I start, or do I need a recovery file as I am not sure I can patch up/down if corrupted… Appreciate your help! I am in the UK EE sim. Ticket has been raised.