X370 Fatal1ty Gaming K4 ALC1220 Audio issues

The problem is the following: 

When I start windows, I hear some static buzzing in the background.

Then after a few seconds, I get a windows has installed some new hardware notification sound, the buzzing dissapears.

Afterwards, the audio level is too loud, I have to turn it down to about 20% to not murder my ears. I have a feeling this is bad for audio quality because compared to the Gigabyte X370/AB350 boards I really notice the difference in quality. In the realtek driver suite I see an option for the Impedence of the headset (which is probably too high for mine) but I can't change the setting. I do see another option with "Dynamic/Balanced/Ultimate?", but changing this doesn't seem to do anything.

Anyone else having these problems, or should I just reset windows and try again with a fresh install?

What bios version are you on? (I read another forum post of a user with similar issues saying this was introduced @ Bios 2.1 for him).

It's a really frustrating issue, not only is the audio level way too loud and crackly, there is also a constant sound like a microphone channel is open giving static background noise. This comes and goes, changing stuff in the windows "Sound" settings (like dis/enabling certain devices randomly) makes it pop up and go away for a while, until it comes back by itself and then goes away again.

Really noone else experiencing issues with this? If so what drivers did you use?

Thanks!

bios 2.20