Firefox: Screensharing with pipewire and wayland in gnome not working as expected

I have problems with screensharing under Gnome, especially using Firefox.

Description of the problem

If I’m participating in a video call using Firefox and a website like Jitsi or Webex, I can’t share my screen with others. If I click the button, a permissions dialogue pops up, the only option being “use system settings”.
If I grant the permissions nothing happens. The screen is not shared and I don’t get a selection dialogue where I could choose the window or screen I want to share.
I don’t get any errors in the browser console either.

If I try this using chromium I can share my screen but it remains entirely black, with only the cursor to be seen if I select the whole screen.
Sharing a single window works, the dialogue that pops up to select the window to share does however not contain all open windows. Some Applications I can share while others aren’t even an option to select.
The same happens with Discord.

relevant software versions

  • Firefox: 98.0.2
  • Chromium: 100.0.4896.60
  • I installed pipewire using manjaro-pipewire. At the moment that is 20220217-2
  • I’m on the stable branch, everything is up to date

I did some research, but all related problems I could find were either outdated, or did not match the problems I described above.
I would greatly appreciate any advice on how to debug this further.

Thanks in advance

It seems that you have similar problems which i have with screen sharing on zoom. Only black and nothing other. It is a Wayland problem. In zoom I could make a workaround with obs sending my screen like a virtual cam. It works great. Do not know if jitsi works with a second cam for sharing. But I wanted to indicate you this possible workaround