Slight update to the original post.
The actual call scenario was as follows;
User A forwards to Hunt Group 1, Hunt Group 1 overflows to User B, User B forwards to voicemail.
With older versions of Connect, callers to User A would eventually end up in Users A's mailbox
With Connect R19.3SP3, callers to User A would eventually end up in User B's mailbox
In the above call scenario User A and B could also be Workgroup A and B.
The issue arises because calls are routing through a Hunt Group.
Good news -
There is a fix to restore call flow behaviour to pre R19.3SP3 behaviour
On HQ Server
Regedit
HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Shoreline Teleworks\Telephony Management Server\Settings
Under that key, double-click the string value SwitchDebug to edit.
Remove the existing period from the end, add a space
Add the setting hunt_pickup 0
Add a closing period at the end to indicate the new end-of-string
A common configuration setting might appear as follows:
debug_options onhook_dialing_for_IP110 1 hunt_pickup 0.
Registry edit is automatically replicated to all DVS's and Voice switches. No reboot is required. Change takes effect immediately.
Mark.