I’ve already gone to settings. Then sounds and notifications and checked my volume. It is all the way up None of the other ringtones are working either. It also should vibrate when it rings but it isn’t. I checked that as well.
If you go to your home screen and press the volume-up button a dialog box should appear at the top of your phone. Have all calls been selected to ring? For some reason my X2 used to switch from All to Priority for no apparent reason.