Unable to paint in Substance Painter after download

Hi,

I just downloaded Substance Painter recently and it won't behave at all.

I am unable to paint in a paint layer most times and when I am able, it paints randomly across my mesh.

Materials work when dropped in but I'm unable to mask because of this paint problem.

I've used the same geo on another computer using a different license (work computer) and it behaves perfectly fine.

Not sure if I had skipped a step in the install or unlock something in the preferences??

😞