I am working a trouble where the users are call forwarding their outside lines (cell, home analog) to their DID. The forwarded call will ring at the Cisco set and then instead of transferring to VM as it should, it gets the "Welcome to Cisco Unity" greeting and the user is given an option to enter an ext. Customer has multiple sites across the country, but this only occurs at one site. When the users fwd their outside lines to DID's at other locations, normal call handling is TOK as calls is CFWD to VM on a RNA.
CUC ver 8.5. CUCM is 8.5.1.1
Any direction given would be appreciated.