I think because Monthly Channel (Target) , also need to do bug report, that is the reason why Microsoft not introduce Monthly Channel (Target) in their web site. For Yearly Channel user, they will get whole year update at the end of the year. For Monthly Channel user, they will get update once a month, and less chance get bug.
I hope you change back to Monthly Channel, all missing part will come back very soon. If not, need to report to Microsoft. KMS activation only due with activation, if lost activation, mainly is windows system get software conflict, corrupt Registry, and corrupted system files etc., need to scan Windows system and solve error.