you can first type AT!GPSEND=0 first, and then try the AT!GPSFIX command.
at!gpsend=0
OK
AT!GPSFIX=1,60,60
OK
ati3
Manufacturer: Sierra Wireless, Incorporated
Model: MC7455
Revision: SWI9X30C_02.30.01.01 r7792 CARMD-EV-FRMWR2 2018/07/13 02:24:52
MEID: 35907206044378
IMEI: 359072060443781
IMEI SV: 16
FSN: LQ648230020110
+GCAP: +CGSM
OK