I've had my iPhone 7 for about 3 months. All was fine...until today. I keep receiving "No SIM card installed" every so often. I've tried all existing troubleshooting steps:
- airplane mode on/off
- shutdown/restart
- reseat SIM card
- check for carrier and OS updates
It's the oddest thing - it works for a while, then it doesn't for a while. Cycle keeps repeating. I've also noticed that my cellular connection no longer connects to LTE (display just says "Verizon" instead of "LTE"). Related to SIM card? Maybe.