Does it help if I share a log output from the FMB920?
10:23:40.979
10:23:40.979 [2004.01.01 00:44:39]-[ATCMD]^I>>[129] +CREG: 2,5,"9742","0000F9BC",0
10:23:40.979 ^J
10:23:40.979 [2004.01.01 00:44:39]-[AT.RSP]^IStatus: 5
10:23:40.979 ^J[2004.01.01 00:44:39]-[AT.RSP]^IArea Code: 38722
10:23:40.979 ^J[2004.01.01 00:44:39]-[AT.RSP]^ICell ID: 63932
10:23:40.979 ^J[2004.01.01 00:44:39]-[AT.RSP]^IRegistration Mode: 0
10:23:40.979 ^J[2004.01.01 00:44:39]-[AT.RSP]^IRegistered To Roaming Network
10:23:40.979 ^J[2004.01.01 00:44:39]-[ATCMD]^I>>[129] OK
10:23:40.979 ^J
10:23:40.979 [2004.01.01 00:44:39]-[ATCMD]^I<<AT+CSQ
10:23:40.979
10:23:40.979 [2004.01.01 00:44:39]-[ATCMD]^I>>[123] +CSQ: 27, 99
10:23:40.979 ^J
10:23:40.979 [2004.01.01 00:44:39]-[ATCMD]^I>>[123] OK
10:23:40.979 ^J
10:23:41.000 [2004.01.01 00:44:39]-[ATCMD]^I<<AT+CBC
10:23:41.000
10:23:41.003 [2004.01.01 00:44:39]-[ATCMD]^I>>[128] +CBC: 0, 93
10:23:41.003 ^J
10:23:41.004 [2004.01.01 00:44:39]-[ATCMD]^I>>[128] OK
10:23:41.004 ^J
10:23:41.004 [2004.01.01 00:44:39]-[ATCMD]^I<<AT+CFUN?
10:23:41.005
10:23:41.007 [2004.01.01 00:44:39]-[ATCMD]^I>>[138] +CFUN: 1
10:23:41.007 ^J
10:23:41.007 [2004.01.01 00:44:39]-[ATCMD]^I>>[138] OK
10:23:41.007 ^J
10:23:41.009 [2004.01.01 00:44:39]-[ATCMD]^I<<AT+COPS?
10:23:41.009
10:23:41.029 [2004.01.01 00:44:39]-[ATCMD]^I>>[125] +COPS: 0,2,"26201"
10:23:41.029 ^J
10:23:41.034 [2004.01.01 00:44:39]-[ATCMD]^I>>[125] OK
10:23:41.034 ^J
10:23:41.037 [2004.01.01 00:44:39]-[ATCMD]^I<<AT+CMGL=4
10:23:41.037
10:23:41.065 [2004.01.01 00:44:39]-[ATCMD]^I>>[127] OK
10:23:41.065 ^J
10:23:41.065 [2004.01.01 00:44:39]-[MOD.TSK]^ISMS Read Map:0,0,0,0 Index:32
10:23:41.065 [2004.01.01 00:44:39]-[MODEM.ACTION]^ISMS Not Found
10:23:41.065 [2004.01.01 00:44:39]-[MODEM.ACTION]^Istatus done
10:23:43.053 [MODEM.STATUS]
10:23:43.053
10:23:43.054 ^ICCID : 898822806670000xxxxx
10:23:43.054 ^IIMSI : 9014053000xxxxx
10:23:43.054 ^IData Link : 0/0/0/0/0/0
10:23:43.054 ^IGPRS Status : 1
10:23:43.054 ^IPhone Status: 0
10:23:43.054 ^IPIN Attemts : 3,3
10:23:43.054 ^IGSM Operator: 26201
10:23:43.056 ^IBat. Charge : 5
10:23:43.056 ^IGSM Signal : 5
10:23:43.056 ^IService : 1
10:23:43.056 ^INew Message : 0
10:23:43.056 ^IRoaming : 1
10:23:43.056 ^ISMS Full : 0
10:23:43.056 ^IVoice Call : 0
10:23:43.056 ^ILAC : 38722
10:23:43.056 ^ICell ID : 63932
10:23:43.056 ^ICFUN : 1
10:23:43.056 ^ICSQ (rssi) : 27
10:23:43.056 ^I[0]SIM detected: 1
10:23:43.056 ^INetwork Type: 1/2G
10:23:43.056
10:23:43.084 [2004.01.01 00:44:41]-[TRACK]^IWARNING @ 55:Time not synchronized!
10:23:45.951 [2004.01.01 00:44:44]-[AXL.CLBR]^IWaiting... (Fix:0 Ign:0)
10:23:48.049 [2004.01.01 00:44:46]-[TRACK]^IWARNING @ 55:Time not synchronized!
10:23:50.957 [2004.01.01 00:44:49]-[OVERSPD]^IScenario disabled!
10:23:50.985 [2004.01.01 00:44:49]-[REC.SEND.1]^IMode: 4/Unknown on Stop. Conditions Failed! Send period:0, periodic data sending skipped
10:23:50.989 [2004.01.01 00:44:49]-[AXL.CLBR]^IWaiting... (Fix:0 Ign:0)
10:23:50.992 [2004.01.01 00:44:49]-[SLEEP]^IWARNING @ 198:Sleep:2, not allowed! Time sync:0, Location:4/0
10:23:53.065 [2004.01.01 00:44:51]-[TRACK]^IWARNING @ 55:Time not synchronized!
10:23:55.971 [2004.01.01 00:44:54]-[AXL.CLBR]^IWaiting... (Fix:0 Ign:0)
10:23:57.976 [GPS.DATA] gps state: ON