Corel Painter 2019 - Intuos Pro pen stuck on dropper tool

Hi there,

I have just picked up Painter 2019 in the humble bundle sale but am having difficulty getting it to cooperate with my Wacom Intuos Pro tablet. Whenever I try to paint with the tablet in brush mode, the cursor becomes the dropper tool (as if alt is being pressed). I can paint with the mouse just fine, it's just when the pen is involved.

Anyone seen this before? I can paint with the tablet just fine in Pixelmator.