nRF9151 don't go to the NTN NB-IoT system mode

[Alterna]

Hello there,

I'm developing a project with NTN using a Vivo chip, a Brazil operator chip, but I'm having trouble with an nRF9151 and I'm trying to put it in NTN mode, but it's giving an error when trying to change its mode and I don't know what to do.
Here are the Serial Terminal logs:

I don't know what to try since this is my first time working with an nRF9151.

Thank you in advance for your attention.

[Syed Maysum Abbas Zaidi]

Hi,

Error 522 on on %XSYSTEMMODE means “Band configuration not valid for selected mode" and it means for the current SIM/operator configuration, the modem finds no valid NTN bands (23/255/256) and therefore rejects the mode as mentioned in the documentation.

So your AT sequence is correct, the issue is due to operator restriction on those NTN bands.

Best Regards,
Syed Maysum