The new Firefox 98.0-1 works OK (at least for what I do with it) on RPi 4 armv7h 32 Bit OS
Firefox 98.0-1 will not launch at all on RPi 4 aarch64 64 Bit OS.
For existing RPi 4 installs
You can go to
/var/cache/pacman/pkg
and use pacman -U to install firefox-97.0.2-1-aarch64.pkg.tar.xz
Then see this post to find out how to not loose your user profile.
Also see @Balder 's next post 3 posts furhter down.
For new installs
I put firefox-97.0.2-1-aarch64.pkg.tar.xz on my personal server.
To download it, open a terminal window into your home page, Then in a temporary folder,
wget https://pudges-place.ddns.net/EndeavourOS/firefox-97.0.2-1-aarch64.pkg.tar.xz
Then use pacman to install it from within the temporary folder
$ sudo pacman -U firefox-97.0.2-1-aarch64.pkg.tar.xz
Reboot and firefox should launch. It will say to create a new user profile, but no big deal since it is a new install.
To prevent the next update from installing firefox 98.0.1, set “IgnorePkg” in /etc/pacman.conf
IgnorePkg = firefox
Then when you update it will nag you about ignoring a package
warning: firefox: ignoring package upgrade (97.0.2-1 => 98.0-1)
When you see the second version is higher than 98.0-1 then you can try it and see if the problem is fixed. But keep firefox-97.0.2-1 around just in case.
Pudge