Group FaceTime not working on iPhone 13

I have an iPhone 13 that I bought a few months ago and Group FaceTime has recently stopped working.

One-on-one FaceTime works but when I try to add another member or call a group chat it doesn’t work. I have tried restarting my phone, turning on and off FaceTime, contact settings, resetting network settings and more but it hasn’t worked.

Whenever a group chat gets called the call doesn’t appear on my end and when someone tries to add someone else to the FaceTime it comes up with a notification saying call failed. However FaceTime works on my iPhone 6s. I initially thought the calls most be redirecting to my 6s so I tried logging out of it however it still doesn’t work for my 13.