Locate Assistive Touch and switch it on. This will cause the Assistive Touch icon to appear on the home screen (white circle on a black background). Turn it on and choose mute and unmute.

This was the answer that member STUART423 gave to someone on the forum in responce as to why their iPhone was not ringing.... He has the best answer of any one that I have seen on an forum...

I had the same problem with my iPhone 7plus and still it would not ring..

When I got the phone as a replacement from Asurion and Verizon, I set it up and all was fine.. RIng was loud and clear.. Problem started when I updated IOS to 11.2.5.. It stopped ringing and my battery life went to 50 % of what it was.. I tried to go back. but Apple has prevented so it was either go back to my good old trusted DROID Maxx or keep going forward.. I allowed the upgrade to 11.2.6 .. My battery life is back to wonderful, but phone would not ring regardless of what I did..

Now in STUART423 advice of chosing unmute, I followed his advice and selected unmute.. Unfortunately here is where I believe the problem lies.. When you turn off your ringer using the side switch, it goes to MUTE with an icon that shows a bell with a slash through it.. This is a universal icon.. NO parking in any country in the world is a P with a slash through it... Bear with me now.. When you get to STUARTS advice about selecting unmute, you have to select the opposite ICON. THis has been the problem that I see has frustrated most people that follow instructions and still get wrong results.. Yes turn off DND, make sure the ringer is on the side switch, but in the in the attentive mode , the bell needs to be showing with the slash, normally indicates mute. NOT the case here..

Its an APPLE software bug created by a programmer who would probably be diagnosed as dyslexic. He was thinking "if you want mute, push this button that shows an ICON that would appear if it was muted.

Any way, after 4 months of no ringer I finally got my phone to ring by selecting the ICON that shows the bell with the slash through it..

Shalom, hope this may clear up some dangling threads.. pj