ngraham added a comment.
On Ubuntu: sudo apt install xserver-xorg-input-libinput sudo apt remove xserver-xorg-input-mouse xserver-xorg-input-evdev xserver-xorg-input-[anything else] [reboot] Package names may be slightly different on non-Ubuntu distros. REPOSITORY R119 Plasma Desktop REVISION DETAIL https://phabricator.kde.org/D8798 To: xuetianweng, ngraham, #plasma, jriddell Cc: jriddell, apol, rkflx, plasma-devel, ZrenBot, progwolff, lesliezhai, ali-mohamed, jensreuterberg, abetts, sebas, mart