The problem was that the NCR user on the BOH has no password. The password does not change by itself.
Once then PW for user NCR on BOH was added, all POSs came back on line.
To Trouble shoot this in the future WHERE ALL POSS showing Backroom offline, MWS order storage offline:
Can you browse between BOH and POSs? If you are prompted to enter UN and PW, then:
Either the BOH or POSs are logged on as different user.
If POSs and BOH are logged on as NCR, then PW of the BOH or POSs have changed.