Pulseaudio audio output problems and libwayland downgrades

[mYnDstrEAm]

I had problems installing pulseaudio on one of my machines running Debian10 with Kodi19 apparently due to mismatching dependencies but not on another machine with almost the same setup. This problem is solved now, probably due to some package upgrades: I could install it now via sudo apt-get install pulseaudio/buster-backports libpulse0/buster-backports libasound2-plugins.

The problem I'm having now is that the audio output still isn't working even when pulseaudio is running (the volume buttons don't work and audio only works for online streaming). I asked about it here. Maybe you have some ideas what might cause that or how to fix it. Another problem that might have to do with this problem is that e.g. sudo apt-get upgrade asks me to downgrade libwayland-client++0 libwayland-cursor++0 which appears to work but right after doing so and even after rebooting it still asks for the same two downgrades as if they weren't downgraded at all. I never deliberately removed pulseaudio. I only had to make this change to a config file to get Kodi audio working properly: setting flat-volumes = no in the /etc/pulse/daemon.conf file (it works neither with nor without and also not with a few other config changes that I've tried). I'm only having these problems on one of my machines and it does have to do with packages installed from your repo.