No Stylus dected

[Alecaddd]

Tablet: Wacom Cintiq 13HD
Passive Wacom Stylus

The tablet connects and works properly, with the screen and orientation recognized.
Even if the stylus works, with its pressure and buttons, it doesn't seem to be recognized by the plug as the "Stylus" Tab always shows the "No Stylus Detected" view.

Do you need any more information? How can I help debugging this?

::UPDATE::

After changing the Tablet mapping from absolute to relative, the stylus is now recognized.

[davidmhewitt]

Can you see if you have libwacom-bin installed and post the output of libwacom-list-local-devices with the tablet connected and the stylus in proximity of it?

Also, you can make the plug "forget" the stylus again by removing its cache with:
rm -rf ~/.cache/io.elementary.switchboard/wacom/

This is the method that would need some debug lines inserted to try and find out where it was falling over with detecting the pen:
https://github.com/elementary/switchboard-plug-wacom/blob/c8c0152149a15591f0920ed24afe00b3d01b85f5/src/Plug.vala#L116-L154

[davidmhewitt]

Actually, I've just had a thought. The plug relies on cursor motion triggered by pen motion to detect the pen. I guess since your tablet has its own screen, switchboard isn't on the same screen as where the pen is, so maybe it's not detected it because of that?

[Alecaddd]

Confirmed your intuition.
I move the switchboard window to the tablet screen and tapped the stylus and got recognized.

[davidmhewitt]

Hm, not sure if there's anything we can technically do about that as I don't think switchboard will be able to pick up cursor events outside of its window. But we could certainly make the instructions clearer 😄