1. Sounds like calls are set to DIL 1:1 to the receptionist, and the FWD/DND is set to forward busy/no answer to voicemail. If forward was changed to forward no answer only to voicemail, then the second call should ring 15 seconds before going to voicemail.

2. Depending on the software version of the TVA 50, I think there was a patch for message cut-offs quite a while ago. Could also be something as simple as incoming message length on the mailbox.