I’m on OpenSuse Tumbleweed (although I’m pretty sure I noticed the behavior on Manjaro, too).

The problem is that the volume of e.g. Firefox gets turned down for no reason. I noticed that a youtube video was quite quiet. I then checkt pavu control and saw that the volume for Firefox was set to 83%. I set it back to 100, but after the pc resumed from standby, it was at 83 again. Sometimes it’s enough to just pause the video for it to move the volume back down.

Why is that and how do I disable this functionality?