I have a Dell Latitude 7390 2-in-1, with a pen. I’m using Manjaro with the standard Gnome desktop environment.
The pen works out of the box, unfortunately for whatever reason it will stop being picked up by the wacom sensor and then it will start being detected again. When it works, the pen functions really well, but these interruptions make it unusable for any actual work.
I’m completely at a loss about how to even start troubleshooting the issue. For example, the command xev, doesn’t seem to announce anything when the stylus/pen is picked up. Also the touchpad and stylus configuration has nothing to help.
Finally I can report that I have a separate Wacom Intuos tablet, which runs over bluetooth, that works reliably.