I'm on a laptop with Wacom touchscreen, Ubuntu 20.04 and KDE 5.18.8.
The stylus and its eraser (activated by a button) is recognized and works well on most part of the screen, except a little area around the upper-centre. When the stylus is moved there, the pointer suddenly jumps on a completely different part of the screen. You can see this effect in a screenshot below. I zig-zagged the stylus on the screen without detaching it (this behaviour doesn not only happen with Xournal++, used to draw this; it also happens on an empty desktop or on other apps.)
I noticed this problem only today, and never experienced it before, at least until I used the stylus a couple of days ago. Neither the laptop or the pen have received any damage in the meantime.
I tried recalibrating by going to Settings>Input Devices>Graphic Tablet>Tablet>Tablet mapping>Calibrate, but the problem persists, even after reboot.
I'd like to understand if this is a calibration problem, software problem, or hardware – in the latter case I have to contact the manifacturer. Any help in how to assess this?
I checked this question but the only answer is related to Gnome. This question is related to external displays, which is not my case. This question & answer and this mention xinput_calibrator, but I'm not sure whether I really need that, given that I already tried calibration from the Settings menu. Finally this question seems to report a different problem, and never received an answer.
The command xinput list (as described in this question) gives (among other devices)
⎜ ↳ Wacom Pen and multitouch sensor Pen stylus id=10 [slave pointer (2)]
⎜ ↳ Wacom Pen and multitouch sensor Pen eraser id=19 [slave pointer (2)]
⎜ ↳ Wacom Pen and multitouch sensor Finger touch id=11 [slave pointer (2)]
and xinput list-props 10 gives
Device 'Wacom Pen and multitouch sensor Pen stylus':
Device Enabled (216): 1
Coordinate Transformation Matrix (218): 1.000000, 0.000000, 0.000000, 0.000000, 1.000000, 0.000000, 0.000000, 0.000000, 1.000000
Device Accel Profile (343): 0
Device Accel Constant Deceleration (344): 1.000000
Device Accel Adaptive Deceleration (345): 1.000000
Device Accel Velocity Scaling (346): 10.000000
Device Node (340): "/dev/input/event9"
Wacom Tablet Area (353): 0, 0, 34399, 21499
Wacom Rotation (354): 0
Wacom Pressurecurve (355): 0, 0, 100, 100
Wacom Serial IDs (356): 21155, -2145366861, 32875, 0, 0
Wacom Serial ID binding (357): 0
Wacom Proximity Threshold (358): 30
Wacom Pressure Threshold (359): 26
Wacom Sample and Suppress (360): 2, 4
Wacom Enable Touch (361): 0
Wacom Hover Click (362): 1
Wacom Enable Touch Gesture (363): 0
Wacom Touch Gesture Parameters (364): 0, 0, 250
Wacom Tool Type (365): "STYLUS" (342)
Wacom Button Actions (366): "Wacom button action 0" (367), "Wacom button action 1" (368), "Wacom button action 2" (369), "None" (0), "None" (0), "None" (0), "None" (0), "Wacom button action 3" (370)
Wacom button action 0 (367): 1572865
Wacom button action 1 (368): 1572867
Wacom button action 2 (369): 1572866
Wacom button action 3 (370): 1572872
Wacom Pressure Recalibration (371): 1
Wacom Panscroll Threshold (372): 1300
Device Product ID (341): 1386, 21155
Wacom Debug Levels (373): 0, 0
