I just installed CentOS 7 on a ThinkPad T420s. All went well. Touchpad worked fine at login screen, in Gnome, and in KDE. KDE is my preferred environment, so I began customizing - including configuring the touchpad to accept "Tapping" gestures via System Settings, Input Devices, Touchpad. As soon as I hit "apply", the touchpad stopped responding to cursor movements. The touchpad buttons continue to work, just no cursor movements with touches. Touch pad is still fully functional at login prompt and in Gnome. However, cursor movements stop as soon as KDE desktop (KDE Plasma) starts.
Any help would be greatly appreciated. I'm almost ready to just re-install CentOS 7 again and not mess with the touchpad settings ever again, but I figure this must be something simple. Other online solutions have not worked, which is why I'm asking here.
Thanks, TW