Well, it’s very strange because i had an iPhone 8 running iOS 13 e everything was fine. Alerts volume was loud and clear. Then iOS 14 came out and suddenly my alerts volume dropped down. Then I bought iPhone 12 mini with the exact same issue.
How is it possible it’s something not related to the iOS?
I’ve tested in a year five iPhone 8, one iPhone 7, one iPhone 6S, one iPhone XS, one iPhone X, five iPhone 12 and one iPhone 13. All of them with low volume alerts issue.
So if it’s not a iOS problem then it must be a hardware problem.
Very strange, ringtones are loud a text tone are weak and all the sounds come out from the same speakers.
Again, perform this test with your iPhone XR:
go to settings, Face ID & passcode (touch ID & passcode for iPhone 7,8 and 8 Plus)
and turn “Attention aware features” OFF.
Then go to “Sound & Haptics”, ringer and alerts volume all the way up.
”change with buttons” OFF
Then in “Sounds and vibration patterns” and set the same sound for both ringtone and text tone. I choose “Sonar” because it’s a very loud sound (you can find it in “classic”).
Set Sonar for both ringtone and text tone and you will hear the volume difference.
Again, it’s an iOS issue and not hardware
and you can tell the difference performing this test.