Phone no longer rings nor plays alert sounds

Update. If you have the Apple watch paired with the iPhone like I do and your phone seems to stay silent on notifications even when the watch notifies, please try unpairing the watch and pairing it back again. This is what I did based on a recommendation from some user on the internet who experienced similar issues after OS 15 update. It seems to have worked. Not sure if anything was silently updated on the operating system. My phone and watch work as expected nonetheless. Both notify and I can silence either or, both or none, as I deem fit. Thanks to the internet user for the suggestion.

Check the ring/silent switch on the left side of the phone. See: How to put your iPhone on vibrate, ring, or silent mode - Apple Support

I have an Apple Watch and and an iPhone. Before this update, my alerts came to both devices and I could get my alerts any way that was convenient, depending on where I was and what I was doing. I could choose to silence either the watch or the phone, or not silence any, especially if I was awaiting critical messages to come through. I contacted Apple Support, talked to three folks. I was informed that I could not have my phone and my watch alert me at the same time, and that if I wanted the phone to alert me, then I needed to lock my watch and keep it locked ... what? More annoying is that the phone alerts when I am using it, but keeps silent when not in use. Really? This is very much inverted intuition and very unfair to me, given the amount of cash spent on these devices. It's a night mare because suddenly, these gadgets do not provide the convenience that I paid for with my hard earned top dollars. Someone did not think through before overhauling the alerting features. Current functionality is very random and buggy, some times the phone will actually alert when not using, 1/10 of the time. Before I knew what hit me, I missed calls, texts, news alerts and whole emails failing to arrive at the iCloud inbox. I am still missing alerts ... I have to stop working, and remember to pick up the phone and inspect it for alerts! Two missed emails were critical emails. I was able to request one of the emails resent to my hotmail account (arrived in seconds!). The other email from DMV for motor-vehicle registration just never arrived, with no way to request a re-send! Apple, please allow me to use my phone and my watch at the same time. This is what was offered to me when I bought these two things and have used them very well until something terrible happened.

I have the same issue...not ringing...silent is NOT on...switch on the side is NOT off.