http://bugs.winehq.org/show_bug.cgi?id=58667
--- Comment #4 from despair.chick@proton.me --- (In reply to Stian Low from comment #3)
(In reply to despair.chick from comment #2)
The application treats single finger as a brush stroke, and multi-touch as a single finger, utilizing whichever one might've hit the canvas first.
Thanks for confirming the correct software.
Just in case it's a factor, what's your touchscreen hardware/model?
I am using a Surface book 3 but I also have access to a pro 7 for further testing. Touch gestures register fine outside of wine when using other art applications such as Krita.