Oh man, I had the Quinn and it was a total piece of junk.

Man, I used to be the guy saying the bigger notch was fine, more glue is better glue. Then I did a hallway with that exact same 3/8 on a rigid core. What a mess. I had to stop every three planks and scrape lines of adhesive off the surface before I could even lock the next one in. It completely changed my process. Now I stick to the 1/4 inch square notch for that stuff, no question. It gives enough grab without the squeeze out nightmare.

Definitely try the driver restart first, it fixes weird pressure issues more often than you'd think. If that doesn't work, take the pen apart carefully and check for any dust or hair wrapped around the spring inside. I've had that kill the pressure before. Also, see if Wacom will do a warranty check, even if it's just out of warranty they might help you out.