Unable to set n257 as preferred band on RG530F-EU module

Technical Subjects
1

Hi, I have a RG530F-EU module in 5GDM01EK evaluation kit. I received the latest firmware from our supplier, which was supposed to solve other issues.

We try to connect the module to 5G SA in n257, so I try to set the band as preferred one with:

AT+QNWPREFCFG=nr5g_band,78:257

It returns:
+CME ERROR: 735

Any hints are really appreciated.

Regards,