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About the FPLMN list

The FPLMN (Forbidden Public Land Mobile Network) list is stored on the SIM and contains networks the device should avoid.
Caution: Only clear the FPLMN when instructed by Hologram support or your device vendor. Doing this at the wrong time can disrupt registration.

Check the FPLMN

AT+CRSM=176,28539,0,0,12
If the response shows 24 Fs, the list is empty:
+CRSM: 144,0,"FFFFFFFFFFFFFFFFFFFFFFFF"
AT+CRSM read showing 24 Fs indicating empty FPLMN

Clear the FPLMN

Before writing, set minimal functionality if required by your module:
AT+CFUN=0
Write exactly 24 Fs:
AT+CRSM=214,28539,0,0,12,"FFFFFFFFFFFFFFFFFFFFFFFF"
Warning: Include exactly 24 Fs in the payload.
AT+CRSM write showing 24 Fs to clear FPLMN
Restore full functionality afterward:
AT+CFUN=1