My SIM card is not being read by my iPhone 6.

My SIM card is not being read by my IPhone 6. I replaced the SIM card and it still was “searching’ with no end. I rebooted, restarted, airplane moded, did a network reboot and still it wasn’t reading the SIM card. I did a diagnostic and it isn’t the motherboard, that was a short lived relief. When I pop out out the SIM tray it comes outs fine. But when closing, there’s a slight amount of resistance, or friction, at the completion of closing the SIM tray. I use an Otter to protect the phone. Does anybody have any ideas or a way to fix this? Thanks.