Since Install 1 User Drops Calls

We have a user (ext. 213) that will be on a call with someone, when another call comes in and goes into a ring group that ext 213 is either a part of, or is the voicemail to go to when the call is unanswered, as soon as someone picks up the incoming call, the conversation on 213 is dropped. in the log I show “span 1 got hangup request, cause 16”.

Anybody have an idea what might be causing this to happen?