Sound on my iPhone 11 still not working unless put on speaker mode

I have had this problem for about a week now and it started after I did an upgrade of my iPhone 11, that I have had for many years. When I get a phone call, the volume is set like at a whisper. As soon as I switch it to speaker phone, it is fine. I have tried taking my cover off and all the other obvious suggestions to date. I even upgraded my phone again but the problem persists. I've turned my phone off and on. Nothing helps. Thoughts?