Yep, looks like it still isn't handled automatically!

You have to do do some little tweaks for it to work.

First, open Firefox and in the navigation bar, write about:config

It will open this page

Then, search for dom.w3c_touch_events.enabled and change the value of it to 1.

Now, close Firefox and open /etc/security/pam_env.conf with your favorite code editor. You will have to use a sudo here as it is normally protected.

At the bottom of the file ,  paste this code:

MOZ_USE_XINPUT2 DEFAULT=1

Now, reboot your computer and you should be good to go ! :)

Post picture by Elia Pellegrini on Unsplash