All sounds work except for notifications on KDE.
I have installed PulseAudio since that worked for some people, but for me it didn't help at all.
Notifications in the system settings are turned all the way up. I have tried doing the test via CMD "notify-send 'text' kdialog --passivepopup 'text' 5"

And the notification pops up for all of them, but no sound is played. In audio I only have 1 device enabled for playback and recording to make sure that they aren't going to any other sound devices.

https://www.bennish.net/web-notifications.html - i tested from this link, notification pops up but no sound for the notification.

pulse audio version is 5.0-2

I have Pop! 22.04
KDE plasma 5.24.7
KDE Framerworks 5.92.0
QT 5.15.3
Kernel 6.2.0-76060200-generic (64 bit) Graphics X11

Hardware Ryzen 7 5800X 32 Gb RAM RTX 2070 super