stich86 I tested CELL LOCK on another modem( router) and another operator , and still works:
+ZCAINFO: 52, 7, 11024, 2850, 20.0; 167, 1, 1, 326, 5.0; 49, 1, 3, 1300, 20.0;
+ZLOCKCELL: 2850, 52
Manufacturer: ZTE CORPORATION
Model: MF286DMODULE
Revision: BD_TELIAMF286DV1.0.0B11
SVN: 11
EDIT: And another way:
+ZLOCKCELL: 1300, 49
+ZCAINFO: 49, 3, 11024, 1300, 20.0; 52, 1, 7, 2850, 20.0; 167, 1, 1, 326, 5.0;
Maybe you should try reset modem by command
AT+CFUN=1,1
instead AT+ZRST....