Firefox 106 Broken WebRTC Screencast on wayland

Hi list,

After upgrading to Firefox 106 screensharing functionality on wayland
stopped working. Firefox ESR (102) still works. I have traced the
breakage to firefox, as no other components of the stack have changed
(sway, pipewire, dbus, xdg-desktop-portal, xdg-desktop-portal-wlr)

It looks like firefox simply stopped trying to use the screencast
functionality - dbus-monitor shows that there are no calls to 
org.freedesktop.portal.ScreenCast interface. No errors, just no attempts
to use it to begin with.

Then I compared firefox and firefox-esr ports and noticed that there is
a generated webrtc patch [1], [2]


Where ESR patch has this line enabled in some cases, non-esr has 0 of
these enabled (the patch only removes these lines)

    DEFINES["WEBRTC_USE_PIPEWIRE"] = True


Questions:
- could this be a reason why WebRTC screensharing stopped working?
- how the patch gets generated?
- maybe there is a reason WEBRTC_USE_PIPEWIRE was disabled on latest
  version?


Thanks

Ihor


[1] https://github.com/freebsd/freebsd-ports/blob/main/www/firefox/files/patch-libwebrtc-generated
[2] https://github.com/freebsd/freebsd-ports/blob/main/www/firefox-esr/files/patch-libwebrtc-generated