Adam, the wayland backend is enabled only when Wayland session is active. KDE does not use Wayland session on Fedora 32/33 so X11 under KDE may be used here. I suspect you see WebRender bugs as WebRender is enabled by default on KDE too. You can set gfx.webrender.force-disabled to false at about:config to force disable WebRender.

Can you please file a bug at bugzilla about the failures and attach a screenshots there? Thanks.

Please install with https://bodhi.fedoraproject.org/updates/FEDORA-2021-fcc0494a63

Please install with https://bodhi.fedoraproject.org/updates/FEDORA-2021-2c3da66ad5

Yes, but -5 contains a minor change which is not important for most users and it's here for OpenQA.

I added dbus-glib as a dependency to firefox-85.0-5

Let's track this as https://bugzilla.redhat.com/show_bug.cgi?id=1908018 as update system isn't suitable for it.

I rebuilt Firefox 84 with in-tree nss and it works a expected. With nss-3.59 from this update the add-ons are broken.

I'll test that.