Automated Attendant / Call Tree records to VM after I hang up

I have inherited an old Asterisk installation that is still working. I am new to this system and am not that great with it, YET. The issue I am having with one user is that they make an outgoing call and get an automated attendant on the line. Shortly after they hang up the message light comes on indicating they have a VM (Cisco system CUCM 11.5 if it matters). When they check the message it is the remainder of the automated attendant menu they did not listen to or just the phone tree repeated that they just listened to.
What is odd is that it is the ONLY phone doing this (or only one reporting it) out of a few thousand device.
Does anyone have any idea why this is?
Any help would be appreciated.
Thank you i

Have you looked at the console output when that user places a call?

What version of Asterisk are you running?

Ah yes that would have helped I guess. It is Ver: C.3.3.2

That’s an almost a decade old commercially supported business version. There will be two problems:

  1. mapping that to a community supported Asterisk version;

  2. remembering how that version actually worked.

Could phone, or hang up handler be doing some kind of transfer to voicemail?

Probably a dumb question, but since it’s just a single phone reported so could it be the user, and not the phone? Are they just hanging up the receiver? Pushing a button on the phone to hang up? Pressing a key (DTMF) to hangup, etc…?

As David mentioned it might be hard to map, and remember how things worked on an older version (way before my time). However you could try posting the relevant section of your dialplan like the extension that was dialed and any hang up handler, and maybe it might clue someone in.

You could also get a pcap, or a SIP trace (could enable through sip debug) of any traffic between the phone and server and make sure there is nothing odd being sent from the phone in a response to hang up for instance.