Thanks for all of your input!
@Aravisian Xorg didn't make a difference unfortunately 
@Ponce-De-Leon Yes, that's where I got it from. I selected the Ubuntu version, was that a mistake?
It works now in the browser of firefox! Only downside: the browser doesn't find my camera.
Steps undertaken to solve camera problem:
- Followed steps outlined in Camera Support 路 linux-surface/linux-surface Wiki 路 GitHub
- Installed libcamera from latest source via git
- Installed mason via pip: $ sudo pip3 install -U meson
- Command cam now lists both front and back cameras
- The app Cheese is working now and able to show and switch between both cameras
- However, Firefox does not recognize the cameras, despite setting media.webrtc.camera.allow-pipewire to true in about:config
Steps undertaken to solve Firefox camera problem:
- Followed the steps How do I set up PipeWire on Zorin OS? to install pipewire
- Firefox still does not recognise the cameras
- Installed wireplumber and ran "systemctl --user enable wireplumber" as well as "systemctl --user start wireplumber"
- Wireplumber does not recognize the cameras
- Set the environment variable "export LIBCAMERA_PIPEWIRE=1", but problem remains
So all in all, I would be happy already if I could zoom in my browser, at least with video. Any suggestions?