FaceTime calls received but can’t make but even then it doesn’t go through with only one contact
So I’ve been having this issue for a few months now but I haven’t been able to find a fix, it only happens with one specific contact but whenever I call them they tell me they don’t get anything, but when they call me I get it but when I accept it’s just a black screen for a moment and then the call fails, it only happens with them and I’m not entirely sure what to do, they don’t have me blocked because I can make regular cell phone calls to them and we’re both on recent versions of iOS, any help is appreciated
iPhone 12 Pro Max, iOS 15