Not receiving FaceTime calls from one person

Up until 2 days ago I cant receive FaceTime calls from one friend. They’ve FaceTimed me and it rings and it looks like I don’t pick up but I just never get the call, I get IMessages though.They also FaceTime other people and those people receive their calls. I had another person FaceTime me and it went through and I was able to pick up. My storage is like less than a GB away from my max and I haven’t updated my phone, I thought this may be the issue but how am I receiving FT from other people then? I also haven’t done anything differently to my phone the last 2 days. Any advice is appreciated. Thank you in advance!