Face Time on Mac opens when it should NOT

Hi, When I use my iPhone during a phone call to switch to hear them on my Mac it opens FaceTime and hangs up the call. FYI- I have already spoke to 5+ advisors and have tried everything except for reinstalling my Macs OS. It didn't use to do this and my phone and Mac are like 2 years old running the latest software. Iphome pro 13 and Mac Pro 16" from 2021.

I can make a new call and use my Mac it's only during a call that this happens, also I have Verizion if that matters.

Bug in IOS or in MAC OS? Thanks in advance.