The settings for touchpad tap-to-click in Plasma desktop are ignored with kernel 5.0. The only way to make tap-to-click work is to add an xorg config file enabling tap-to-click, but at this point it cannot be disabled from Plasma KCM configuration module. I think this is a kernel issue since with kernel 4.20 and 4.19 everything works as expected. The issue has been filed also on KDE bug tracker: https://bugs.kde.org/show_bug.cgi?id=406778 System: Dell XPS 15 9570 $ dmesg |grep Touch 1216:[ 3.814366] psmouse serio1: synaptics: Touchpad model: 1, fw: 8.2, id: 0x1e2b1, caps: 0xf00123/0x840300/0x12e800/0x0, board id: 3125, fw id: 2378871 1217:[ 3.850630] input: SynPS/2 Synaptics TouchPad as /devices/platform/i8042/serio1/input/input9 1234:[ 4.833956] input: SYNA2393:00 06CB:7A13 Touchpad as /devices/pci0000:00/0000:00:15.1/i2c_designware.1/i2c-10/i2c-SYNA2393:00/0018:06CB:7A13.0001/input/input15 1250:[ 5.008216] input: SYNA2393:00 06CB:7A13 Touchpad as /devices/pci0000:00/0000:00:15.1/i2c_designware.1/i2c-10/i2c-SYNA2393:00/0018:06CB:7A13.0001/input/input24 Archlinux with kernel (linux-ck) 5.0.9-1 libinput 1.13.1-1 xf86-input-libinput 0.28.2-1 xorg-server 1.20.4-1 synaptics is not installed KDE Plasma Version: 5.15.4 KDE Frameworks Version: 5.57 Qt Version: 5.12.2-2