I can't make a a regular phone call, FaceTime (wi-fi), or text message to a certain person. We can only contact each other at certain times of the day and they're random and then the call drops after awhile. We use FaceTime audio because it's clearer and iPhone message. They're a Sprint user and has the iPhone 10 and I have the iPhone 11. I had this problem for awhile now. Our convos are always random and sometimes it just never works. I reset my network settings and even reset my iPhone even though it's new and switched to Verizon from At&t thinking it was a network problem. I don't know what to do; it's irritating.