Facetime Join Request at 2am - Group Text Message Thread

We have a group text message thread that has been active for a very long time. Over the past many months I will get a random 2am Facetime Join Request from one individual's iphone. It's always at 2am or 2:01am or 2:02am. It happens often. If I ask everyone else on the thread no one else gets it and the "sender" has no idea it's happening either. I have multiple screen shots from the last couple nights.