Here’s a repeat of a post I made some time ago:
There’s a basic test you can do to make sure that the stylus is sending good pressure signals to krita.
Go to Settings -> Configure Krita -> Tablet settings and click the large ‘Open Tablet Tester’ button. A ‘Tablet Tester’ window will open and you can drag it and resize it to make it conveniently large.
If you draw on the grid area on the left, you’ll see a log of the signals that krita sees on the right side.
Here’s what I get if I vary the pressure of my stylus while drawing:
The short blue line is what I drew and you can see on the right that my stylus was giving pressure in the range of 0% to 100%.
Those lines of text are produced very quickly and you’ll probably need to scroll the right hand side up and down to see them all.
You can click the Clear button and try again if there’s too much text in there.
Until you can see pressure in the range 0% to 100% in the tablet tester, there’s no point in trying to edit/design brush presets.
Also: In the image you uploaded, you’ve set Y-tilt to control the Size. Does your stylus have tilt sensitivity?