A Glonass tracking issue has been reported worldwide. It caused some GPS receivers to stop tracking Glonass and sometimes GPS.
We haven't heard if the Russian Federal Space Agency has resolved the problem, but we are seeing Glonass at our sites this morning.
I suggest trying RTCM3, but switch to RTCM2 if you see Glonass not being used in your solution or you have problems getting a fixed solution. RTCM2 doesn't use Glonass so the GPS satellites shouldn't be affected, and you should be able get a fixed solution (assuming there are enough GPS satellites). CMR and CMR+ shouldn't be affected.