If the issue persists after these steps, the problem may be with the SIM card itself or the carrier settings. Try using a different SIM card to isolate the issue. If the problem is with the SIM card reader on your iPhone 6, it may require professional repair or replacement.
When to Seek Professional Repair
If the simple troubleshooting steps do not resolve the issue, and you have confirmed it is a problem with your iPhone 6’s SIM card reader, it is best to seek professional repair. This may include:
Visiting an Apple Store or authorized service provider for repair or replacement of the SIM card reader.
Contacting your carrier for assistance, as they may be able to provide a replacement SIM card or troubleshoot the issue further.
Using a third-party repair service that specializes in iPhone repairs, but be sure to research their reputation and use caution when entrusting your device to an unauthorized service provider.