The work-around in our experience, has been to have the user re-record their name, or to have a system administrator removed the recorded name via UC admin. This fixes the mailbox exhibiting the problems, though the same issue does appear to randomly & rarely appear for another mailbox.
We're on 8.6.2 & plan to upgrade per TAC recommendations to a version within 8.6.2 that does not have this issue.
hitting Bug - CSCuh43453
To resolve the Bug, please upgrade Unity Connection to 8.6.2(SU5).
Perhaps this information helps others with a possible temporary work-around.
