Updated to the latest OSX Mojave, and now the first brush stroke after picking a color(Option hotkey pressed and released before painting) on the canvas is not working properly, it does a straight line as if Shift was held down.
The problem was there before i updated to 20.0.1 and only had updated to Mojave
Tested in Photoshop 18 and Autodesk sketchbook, no problem.
Hope there is a fix for it soon.