I have a single user of an 8622 whose phone resets to FWD to Voicemail each night. This extension used to be a Phantom Device, but is now a Station. The extension used to be an Agent ID. The user once used Xarios for Hotdesking, but no more. He is not an Agent in the Xarios Hotdesking hunt group.

Any ideas

So Ext. XXX started our as a true phantom, became a real station, then that user was an Agent ID for a while and now the station forwards itself to VM every night?

I don't know anything about Xarios. Does it have 3rd party call control like Intelligent Router or UC?