Ubuntu 22.04 is using wayland display server. Apps either use wayland natively , or via an X / xorg compatibility layer. (Xwayland). See also How can I tell if an application is using XWayland
On my box, most apps are native wayland, but firefox by default is using Xwayland.
Input event handling
I believe input events are handled by libinput. If I run the tool
libinput debug-events from libinput-tools package, it shows events for two finger scroll. The docs describe how to configure input devices for wayland apps and xorg apps.
xinput does not anymore seem the right tool to configure input devices. See warning in man page. If at all, it can only configure apps using the Xwayland compatibility layer.
Change two finger scroll speed for native wayland apps
For wayland apps the libinput FAQ is stating:
Use the configuration tool provided by your desktop environment (e.g. gnome-control-center)
Since the ubuntu settings are currently not provide an option to configure two finger scroll speed, I believe it is currently not possible to do this.
Improve scroll speed for firefox
You can make firefox to use native wayland instead of Xwayland and for me it is improving the scroll speed ( slowing it down ). How to do it:
sudo gedit /etc/environment
- Add one line at the end of the file, containing this string:
- Reboot system
Hope this helps