I have a Veikk S640 drawing tablet, and one of the problems with it on Linux is that the x-axis doesn't get updated when the pressure-axis gets updated, leading to staggered strokes like these in Xorg in KDE Plasma. The top stroke is from Gimp, while the bottom stroke is from Krita. This doesn't look like only the x-axis not giving input, but that's what the xinput test command says:
button press 1
motion a[0]=4641 a[1]=12079
motion a[0]=4641 a[1]=12069 a[2]=598
motion a[0]=4665 a[1]=12047
motion a[0]=4665 a[1]=12057 a[2]=608
motion a[0]=4678 a[1]=11987
motion a[0]=4678 a[1]=12018 a[2]=614
motion a[0]=4695 a[1]=11984
motion a[0]=4695 a[1]=11999 a[2]=621
motion a[0]=4710 a[1]=11922
motion a[0]=4710 a[1]=11956 a[2]=562
motion a[0]=4719 a[1]=11909
motion a[0]=4719 a[1]=11930 a[2]=419
motion a[1]=11834
motion a[1]=11876 a[2]=268
motion a[1]=11826
motion a[1]=11848 a[2]=0
button release 1
The y-axis(a[1]) gets updated every step, while every time the pressure-axis(a[2]) is updated it seems to cause the x-axis(a[0]) to not update.
This seems to only be a problem in Xorg, but I can't switch to Wayland as the pressure doesn't work in any program there.
This is specifically a problem in the KDE Neon distribution. I tried several different distributions, even some with up to date KDE Plasma such as Kubuntu, and had no problems. I wasn't able to track down if there was a specific package in KDE Neon causing this. I've moved onto Kubuntu as a workaround now since it works, but can't provide a fix.
