UCM version is 11.5
Created new Device profiles and End user with BAT and tested on the 8945 and 8845 model in our remote office 1 and they were successfully with EM profile.
While testing on the newly installed 8851 at another new site, we were not able to login with same EM profiles that were built in office 1 before the users.
Then reset the password for End-user profiles, no luck, again on EU profile delete and rebuilt then it was successful but there are 100 EU which is very tedious and also they are associated with UCCX as Agents.
End-user profile, Go to -> Service SETTING option--> home Cluster , Check is required. that fixed the issue. it was very simple to enable on each profile quickly. Issue got resolved.