iPhone rings loud then quiet

Go to settings, general, accessibility, Face ID and attention, turn off Attention Aware Features.

If you don't do what's recommended above, your phone is lowering the volume on the ringtone on purpose because it realizes you've engaged your phone by picking it up. At first, I found this disconcerting, but now I absolutely love this because in an office situation, the incoming ringtone volume goes down on purpose, making it less loud for the those around me. The volume won't go down on an incoming ring unless you actually pick your phone up, or tap the screen if you have tap to wakeup enabled.

Rbrylawski, your explanation is a great one, much better than my simple one to turn it off. Perhaps the OP would like to keep it on., based on your comments. I had the same "problem" and couldn't figure out what was happening. I called Apple support, and they helped me find the Attention Aware Features setting.

I thought my phone was faulty, too. I was soooooo mad! I was waiting for this phone anxiously, and then "it didn't work", or so I thought.

It's actually a great feature, and I can tell you, that everyone, I mean EVERYONE, in my office is super grateful I have this phone! LOL

LOL! So they'll allow you to work there for...at least another couple days, huh? LOL

I'm top producer in my office so I'm guessing they will. But they sure hate my ringtone and are ever so grateful the tone diminishes in volume as soon as I engage my phone.

If I may ask, what is your ringtone that they don't like? The ringtone I just managed to purchase is the 1812 Overture. I'm sure to make enemies with that one blasting.

It's a Libera Song, which is beautiful. Rather new age'ish and pleasant. The guys around me just hate it.

Lol. They should look at the bright side: at least you don't have the Harmonicats, the Moms and Dads, or Weird Al Yankovic.

They'd likely prefer those options better. LOL