Missed Calls

1. Check to see the Silent switch is not set to ON. Silent switch is located on the Top Left Side of your iPhone.
2. Check to see that Do Not Disturb is set to OFF. Open Settings ➔ Do Not Disturb : Set his to OFF
3. Check to see that Silence Unknown Callers is set to OFF. Open Settings ➔ Phone ➔ Silence Unknown Callers : Set this to OFF
4. Make sure that a ringer sound is assigned. Open Settings ➔ Sounds & Haptics ➔ Ringtone : Ensure that a Ringtone is assigned here.
5. If all of the above is OK on your iPhone then Try and Force Restart your iPhone EXACTLY as shown below and see whether that resolves the issue:

• Press and quickly release Volume UP button
• Press and quickly release Volume DOWN button
• Press and Hold the SIDE button until an Apple logo appears and then release the Side button (Can take up to 20 seconds. (DO NOT release Side Button when invited to Slide Power OFF). 

Axel F.

Check the settings.

Settings>Phone>Silence Unknown Callers.