I'm using the Spitz AX (GL-X3000NR) in the UK with an EE SIM and have a strange issue to report. Initially when I set the SIM up, the only connection was LTE FDD (4G+). I had tried using the IMEI of a spare phone but the connection wasn't able to achieve a NR5G-NSA connection.
I then tried using a Vodafone SIM in slot 2 to evaluate speed and decided to stick with my EE SIM as it is several times quicker in my area. This is where my issues started. Changing back to the EE SIM, the Spitz could no longer connect using the EE SIM, it would always say "SIM card not registered" - even though the SIM worked fine in a phone. Performing a factory reset also did not work. I also re-flashed the firmware, but I think that also did "nothing" that a factory reset wouldn't have already done.
What eventually worked (although maybe it is coincidental and a timing related issue with the local towers by using the EE and Vodafone SIMs using the same IMEI?) was running these commands, I can't remember the exact order:
AT+CFUN=1,1
AT+CFUN=0
AT+CFUN=1
Upon a reboot, my EE SIM could connect once more, but rather than connecting with only LTE FDD, it is connecting with NR5G-NSA, great!
What would cause the above behaviours? Do the above commands do anything that a reboot or factory reset would not accomplish?
Spitz firmware: 0408release4 (2024-04-19)
Quectel firmware: RM520NGLAAR03A03M4G_01.201.01.201 (2024-03-28)