You didn't mention which version, but this is a known defect that was introduced in 8.5 and may affect UCM as well as Unity Connection. We have experienced it in CUC 8.6. The defect is unresolved but can be manually fixed with TAC's assistance via...
There is a bug (CSCsx49385) that resembles that behavior somewhat; has the agent's username been edited recently in UCM or AD?Sent from Cisco Technical Support iPhone App
