Attaching GPRS fails

I am trying to connect NB-IoT deluxe shield(with Sara N-210 modem) to network using Sodaq_nbIOT.h library. It starts waiting for signal quality, takes ~20 seconds until reads +CSQ:30,99 (im testing only ~200m away from the cell tower), then tries to attach to network and fails there. And these results are consistent.
I have done the same AT commands procedure by using serialpassthrough, result is same.
APN and operator code are correct, it is confirmed by the service provider.

I also know from service provider that their LTE cell bandwith is 10mHz, EARFCN is 6300. There is AT command to set EARFCN but no way to set the bandwith. So can the problem be in LTE cell bandwith?
Also when i have set “AT+NEARFCN=0,6300”, response is “OK”, but when i send AT+NUESTATS, it shows NEARFCN = 0. Is that maybe a firmware bug?
Current firmware is V100R100C10B655SP2

Thats a lot of questions but hopefully somebody is able to help me out
Thanks in advance