Agent Hang Ups

Hello!

We have our queue set to auto answer. Recently we have noticed calls being transferred from that queue to our overflow queue, and in the event details it appears the call is accepted and then our agent 'hangs up' shortly after acceptance. Luckily it goes to our overflow queue so we don't lose the call, but is this my agent doing that intentionally or is there a setting they could be triggering? Agent claims to not be doing it themselves. Is there a place we can track these 'hang ups' to see if its more than one agent doing it?