Você tem que usar o xinput para desabilitar o Rolagem Natural.
Terminal aberto:
~$ xinput list
A saída deve ser algo como:
⎡ Virtual core pointer id=2 [master pointer (3)]
⎜ ↳ Virtual core XTEST pointer id=4 [slave pointer (2)]
⎜ ↳ USB Keyboard id=10 [slave pointer (2)]
⎜ ↳ ImPS/2 BYD TouchPad id=11 [slave pointer (2)]
⎣ Virtual core keyboard id=3 [master keyboard (2)]
↳ Virtual core XTEST keyboard id=5 [slave keyboard (3)]
↳ Power Button id=6 [slave keyboard (3)]
↳ Video Bus id=7 [slave keyboard (3)]
↳ Power Button id=8 [slave keyboard (3)]
↳ USB Keyboard id=9 [slave keyboard (3)]
↳ USB Keyboard id=12 [slave keyboard (3)]
Olhe, TouchPad id = 11.
~$ xinput list-props 11
A saída deve ser algo como:
Device 'ImPS/2 BYD TouchPad':
Device Enabled (135): 1
Coordinate Transformation Matrix (137): 1.000000, 0.000000, 0.000000, 0.000000, 1.000000, 0.000000, 0.000000, 0.000000, 1.000000
libinput Accel Speed (274): 0.000000
libinput Accel Speed Default (275): 0.000000
libinput Accel Profiles Available (276): 1, 1
libinput Accel Profile Enabled (277): 1, 0
libinput Accel Profile Enabled Default (278): 1, 0
libinput Natural Scrolling Enabled (271): 1
libinput Natural Scrolling Enabled Default (272): 0
libinput Send Events Modes Available (255): 1, 0
libinput Send Events Mode Enabled (256): 0, 0
libinput Send Events Mode Enabled Default (257): 0, 0
libinput Left Handed Enabled (279): 0
libinput Left Handed Enabled Default (280): 0
libinput Scroll Methods Available (281): 0, 0, 1
...
Veja isto, Libinput Natural Scrolling Enabled (271): 1.
Você precisa defini-lo como 0.
xinput set-prop 11 271 0