I'm really enjoying the software but I've run into the problem of the program not respecting my Wacom settings on the Wacom pen 2 and my Cintiq 24. If I set set one of my pen buttons to "RMD (Right mouse button) it simply doesn't recognize it as a right click, it seems to replace it with a normal click or something. On rare occasions it seems to work in the UV window but it stops working after a bit, and never in the 3d view.
The Wacom pen 2 seems to work fine on the Wacom pro tablet but not on the Cintiq pro 24, so must be something with that driver not working well with the software. The first release of Substance Painter 2018 had the same issue but it got fixed in the patch soon after the release. I hope you can find the bug, using the program with a tablet makes things so much faster