So, for some reason, it appears that the pressure sensitivity funtionality for some users of Wacom does not work on Windows 10. After having looked all over the net, I never found a real solution.
There was some solutions that would make it work for a single session, but for each restart of Windows, it would be back to not working, and it would have to be done one more time.
However, I found this suggestion to a solution (The Wacom sensitivity Solution)… and it worked.
The name have changed a bit since this article was created, and you should now do the following instead.
Start -> Wacom Tablet Preference File Utility
From here you “Remove” All User Preferencess.
If it does not happen automatically you should re-calibrate your Wacom
Start -> Wacom Tablet Properties -> Calibrate
Click on “Calibrate” and follow the instructions.
Not, pen pressure sensitivity should be working again.