Problem: pen pressure needs to be strong to register, except when button pressed on pen

A pressure sensitive pen only starts painting if
- a button on the pen is pressed beforehand (and then the pen touches the screen)
- sufficiently strong pressure is applied to the pen on the screen

This happens in generally in KDE, in different applications (gimp, krita, rnote..)

This has not been the case a few weeks/months back (I cannot pinpoint when this started happening)

It looks like the pen is handled like a mouse. A "click" either in form of enough pressure or button-press is necessary to lead to drawing. 

This is not how a drawing tablet (galaxy s9 with an s-pen) is handling pressure sensitive pens. It is also not how it was handled before in KDE. 

Desired behavior is, that any touch of the pen on the screen will register as stroke, even a light one. With more pressure amounting to a stronger stroke. 

This bug renders drawing with pressure practically useless. One cannot draw on a laptop screen without holding the physical screen with one hand, because the pressure necessary for the pen to register pushes the screen backwards. One also does not know at what exact moment enough pressure is reached for a stroke to start appearing.