Borderline unstable notification sound volume

I'm sorry if this has been discussed before, but I couldn't find it.

I'm using an iPhone 13 on iOS 26.3. Ever since like iOS 26 has released (I really can't say if it didn't happen on iOS 18, definitely not earlier though) the notification sounds (or rather, system sounds in general) are absolutely BROKEN. They very often are either too quiet, to a point where they are literally not playing any sound at all, only the vibration being audible, or absolutely TOO LOUD, where I'm getting constantly jumpscared by a notification out of nowhere. This very often changes without me even touching the phone. The very same thing applies to sounds like screenshot sounds too.

inb4 i do NOT have the "change with buttons" setting enabled under rings and alerts in Settings. Slightly moving the volume slider fixes the issue for a while, but it sometimes doesn't even take a few minutes before it's broken again.

I'm genuinely annoyed by how buggy this system became starting with iOS 18 and even more with the 26, even after all these bugfixes. I'm really convinced it has to be far less buggy on newer iPhones, because there's no way they've been letting this slide for so long. This isn't the only issue, but this specific one is genuinely preventing me from using my phone as a phone.