All of MNDOT CORS mounts supply GPS+GLONASS with the corrections.  For whatever reason, I used to have better luck with all the Trimble receivers (FMX included) to run RTCM 3.1 with MNCORS. I would get the same thing where it would randomly go into float with CMR.   I run on a private cellular network now.

SOURCETABLE 200 OK
 Server: NTRIP Trimble Ntrip Caster 3.8
 Content-Type: text/plain
 Content-Length: 2088
 Date: Thu, 18 May 2017 21:17:01 UTC
 STR;CMR_Plus_NAD83(2011);CMR Plus NAD83(2011);CMR+;Obs(1),Info(10),PrsInfo(11);2;GPS+GLONASS;MNDOT;USA;0;0;1;1;Trimble Pivot Platform;none;B;N;0;;
 STR;CMRx_NAD83(2011);CMRx NAD83(2011);CMRx;Obs(1),Info(8),PrsInfo(8);2;GPS+GLONASS;MNDOT;USA;0;0;1;1;Trimble Pivot Platform;none;B;N;0;;
 STR;AGRTCM31;AGRTCM31;RTCM 3.1;1004(1),1005/1007/1033(5),1012(1, all msgs),4094;2;GPS+GLONASS;MNDOT;USA;0;0;1;1;Trimble Pivot Platform;none;B;N;0;;
 STR;RTCM_23_NAD83(2011);RTCM 23 NAD83(2011);RTCM 2.3;3(6),18(1),19(1),22(6),23(5),24(5);2;GPS+GLONASS;MNDOT;USA;0;0;1;1;Trimble Pivot Platform;none;B;N;0;;
 STR;CMR_Plus_NAD83(2007);CMR Plus NAD83(2007);CMR+;Obs(1),Info(10),PrsInfo(11);2;GPS+GLONASS;MNDOT;USA;0;0;1;1;Trimble Pivot Platform;none;B;N;0;;
 STR;CMR_Plus_NAD83(1996);CMR Plus NAD83(1996);CMR+;Obs(1),Info(10),PrsInfo(11);2;GPS+GLONASS;MNDOT;USA;0;0;1;1;Trimble Pivot Platform;none;B;N;0;;
 STR;CMRx_NAD83(2007);CMRx NAD83(2007);CMRx;Obs(1),Info(8),PrsInfo(8);2;GPS+GLONASS;MNDOT;USA;0;0;1;1;Trimble Pivot Platform;none;B;N;0;;
 STR;CMRx_NAD83(1996);CMRx NAD83(1996);CMRx;Obs(1),Info(8),PrsInfo(8);2;GPS+GLONASS;MNDOT;USA;0;0;1;1;Trimble Pivot Platform;none;B;N;0;;
 STR;RTCM_23_NAD83(1996);RTCM 23 NAD83(1996);RTCM 2.3;3(6),18(1),19(1),22(6),23(5),24(5);2;GPS+GLONASS;MNDOT;USA;0;0;1;1;Trimble Pivot Platform;none;B;N;0;;
 STR;RTCM_31_NAD83(2007);RTCM 31 NAD83(2007);RTCM 3.1;1004(1),1005/1007/1033(5),1012(1, all msgs),4094;2;GPS+GLONASS;MNDOT;USA;0;0;1;1;Trimble Pivot Platform;none;B;N;0;;
 STR;RTCM_31_NAD83(1996);RTCM 31 NAD83(1996);RTCM 3.1;1004(1),1005/1007/1033(5),1012(1, all msgs),4094;2;GPS+GLONASS;MNDOT;USA;0;0;1;1;Trimble Pivot Platform;none;B;N;0;;
 STR;AGCMRP;AGCMRP;CMR+;Obs(1),Info(10),PrsInfo(11);2;GPS+GLONASS;MNDOT;USA;0;0;1;1;Trimble Pivot Platform;none;B;N;0;;
 STR;AGCMRX;AGCMRX;CMRx;Obs(1),Info(8),PrsInfo(8);2;GPS+GLONASS;MNDOT;USA;0;0;1;1;Trimble Pivot Platform;none;B;N;0;;
 STR;RTCM_31_NAD83(2011);RTCM 31 NAD83(2011);RTCM 3.1;1004(1),1005/1007/1033(5),1012(1, all msgs),4094;2;GPS+GLONASS;MNDOT;USA;0;0;1;1;Trimble Pivot Platform;none;B;N;0;;
 ENDSOURCETABLE