@emelie it's fuckery related to how windows lets applications use pen tablets
the old style of interface is called "wintab", but the thing being used by default now is "windows ink", photoshop integrates with the latter but krita doesn't by default
since windows ink, unlike wintab, offers stuff like gestures, you get a delay while windows is trying to "figure out what you do", since long pressing on one spot will right click