Answer:
There can be several reasons why an iPhone may not ring for incoming calls. Some possible causes include the volume for calls being set to mute, a damaged speaker, the iPhone being stuck on headphone mode, Do Not Disturb (DND) or Focus mode being turned on, or the caller’s phone number being blocked 1.
To fix the issue, you can try turning up the volume in the Settings app, checking and turning off DND or Focus mode, or checking for other possible culprits such as CarPlay or Calls on Other Devices.