No audio and network freeze running Linux (Ubuntu, Fedora) on an XPS 15 7590 w/ WD19TB

I am currently running Ubuntu 20.04 on my XPS 15 7590. Here everything works like a charm. When working at my desk I connect my monitor and peripherals using my WD19TB docking station connected over Thunderbolt. Here I run into two (small) problems.

• I have no audio from both the speaker connection and the headphones connection. Both are recognized by the OS, but there is no audio. I have been playing around with ALSA, but without any success.
  
  Now using bluetooth audio, but I would really like to use a wired audio connection when connected to the docking station.

• When connected to an ethernet cable all works as expected until I shut down the computer. A few minutes after I shut down the computer my home network completely appears to freeze / hang up, every device on the network loses it's connection. Disconnecting the ethernet cable from the docking station or (re)starting the laptop solves this problem. I notice the left led on the ethernet port (link) of the docking station stays on after the computer shuts down (when running Windows 10 it does not). When using a USB ethernet adapter directly connected to the laptop (being disconnected from the docking station at that time) the problem does not occur.
  
  Now connecting to my network using wifi, but here too - I would really like to use a wired connection when connected to the docking station.

I have experienced both problems with Ubuntu 20.04 - also with Ubuntu 18.04 and several Fedora versions. When installing and running Windows 10 everything works as expected.

Has anyone else experienced these problems and maybe solved them? Or does anyone have an idea that might solve these problems?

Thanks in advance.