EM7565 - Not able to control roaming flag

Hi,

I have 40+ of these EM7565 modems which are intended to be used on our private LTE network.

We have our own SIM cards (MCC 001 - MNC 01), which will be used on the LTE network hardware supplied by our partner to us. (different MCC - MNC)

In other words, the modems will actually attach to the network in Roaming mode.

While most of these modems seem to have roaming enabled by default, some of them don’t, and some of them suddenly stopped roaming after a while, only to figure out that the roaming flag got disabled suddenly.

It seems it’s not possible to control Roaming capabilities of the EM7565.

See below:

Terminal ready
ati3
Manufacturer: Sierra Wireless, Incorporated
Model: EM7565
Revision: SWI9X50C_01.08.04.00 dbb5d0 jenkins 2018/08/21 21:40:11
IMEI: 353533100150005
IMEI SV: 8
FSN: UF918475470215
+GCAP: +CGSM

OK
at^sysconfig?
^SYSCONFIG: 2,0,1,2

OK
at^sysconfig=16,3,0,4
+CME ERROR: operation not allowed

at^sysconfig?
^SYSCONFIG: 2,0,1,2

OK

at^sysinfo
^SYSINFO: 2,3,0,9,1

OK

This command works on all other Sierra Wireless modules we have (EM7455 and others)

Any idea?