I found the problem with my phone. I can get data, internet, text, but no voice phone. It turned out to be the radio antenna for phones calls. The grey wire on the right side was getting pinched when I screwed the back on. I also lifted the usb flex circuit board slightly, from the right. Cleaned the contact between the board and the antenna contact on the frame and pressed it back. That fixed it. So, check your grey wire connections or try replacing the wire.
Phone radio has a different antenna than wifi, 4g, Bluetooth. Etc.