I wonder if this is more of an X problem, or one of Plasma?
I have a machine with touch screen. Kubuntu works well on it, but is close to useless, because whatever I have been doing, I am unable to exert a right click. Neithetr with the finger nor with the pen can a context menu be brought up. On W10 (dual boot, alas) a longer peroid of resting of the finger or pen tip swap from left click to right click.

Can anyone help me with this, and indicate how a right click can be generated through the touch screen, please?