If SMs/CPE got deregistered from all APs and all APs are rebooting at the same time then obviously the problem is with CMM or its power supply.
If APs are not rebooting and also not losing web access just deregistering CPEs/SMs then
- check if CMM is losing GPS information and losing sync
- check GPS antenna by changing the location and by swapping it with working one
- check if GPS can see clear open sky
- check cable and connector for GPS antenna coming in CMM
- check CMM by swapping it with known and working one