Newer versions of Kubuntu are missing the advanced mouse options which let you debounce the mouse
sudo apt install xserver-xorg-input-evdev sudo mkdir -p /etc/X11/xorg.conf.d
Then edit /etc/X11/xorg.conf.d/xorg.conf
and append:
Section "InputClass" Identifier "evdev-mouse" MatchIsPointer "yes" Driver "evdev" EndSection
You may have to reboot at this point
xinput --list # find the id of the mouse (e.g. 10) xinput --list-props 10 # list the properties of this id xinput --set-prop --type=int --format=32 10 286 20 # set debounce of ID 10 to 20 (can go up to 50 if need) xinput --list-props 10 # repeat and see last item is KP0 (286): 20
Test out this value and see if it works.
If it does then create the file /usr/share/X11/xorg.conf.d/12-evdev-debounce.conf
to make the change permanent
Section "InputClass" Identifier "evdev pointer debounce" MatchIsPointer "on" MatchDriver "evdev" Option "DebounceDelay" "20" EndSection