Secret Keyboard code in KDE/Plasma?

[Hans <hans.ullrich@loop.de>]

Hi Folks, 

does somebody know, if there is a secret code or key combination, that 
switches off the internal keyboard in a laptop?

It is since years, that suddenly the keyboard is deactivated during typing. As 
I am not a good typist, it happens, that I am pressing some keys together or 
touching the touchpad during typing, too.

This happens only in KDE / Plasma5, in any other windowmanagers like LXQT, 
XFCE or LXDE this issue never appeard.

I could not discover this, when I deactivated the touchpad in KDE (which is of 
course not wanted), but that might be by pure chance.

There appeared nothing about this in any logs.

Does someone know more?

Best regards

Hans