Some brushes not working with Wacom Pro Pen 2

I have recently been having a very troubling issue with some brushes in Fresco, there is no rhyme or reason to it that I can identify, aside from it seeming to be confined to pixel brushes. 

Some brushes simply dont work, at all, when I'm using my stylus (they do work when I use the mouse).

I'm using a Pro Pen 2 on a Wacom Cintiq Pro 24, all Wacom drivers are up to date, as is Windows, as is Fresco (letest version).