Phone rings briefly the stops then rings again

Hey Slinky00,

If there is problem connecting to only one contact, you could try to remove the contact and recreate it. Also try to update the carrier settings on the iPhone.

Manage and delete contacts on your iPhone, iPad, or iPod touch - Apple Support

1. "Make sure that your device is connected to Wi-Fi or a cellular network.
2. Tap Settings > General > About.
3. Follow the onscreen instructions to install your carrier update."

Manually update your carrier settings on your iPhone or iPad - Apple Support

Please don't hesitate to let us know if you need additional assistance.

Thank you for using Apple Support Communities. Have a good one.

Slinky00,

Got it. It appears that you already have the latest carrier settings installed. To clarify, are you using Wi-Fi Calling? If so, go to Settings > Phone > Wi-Fi Calling and turn off this feature to see if the issue persists.Click here for more details: Make a call with Wi-Fi Calling

If not, reset your network settings to see if that helps. Go to Settings > General > Transfer or Reset iPhone > Reset > Reset Network Settings. This will erase all current saved settings, including Wi-Fi passwords, preferred networks, and VPN settings.

Also, go to Settings > General >Software Update to verify that you're running the latest version of iOS 15: Update iOS on iPhone (Secure your data with a backup prior to updating)

If you continue to experience the same behavior, contact your carrier to make sure that there aren't any outages or that your calls do not have any errors on the carrier system.

Let us know if this helps. Stay safe an d well!