when using the ondrag behaviour for an element there's no prefentDefault attached for touchstart, touchmove?!so when dragging vertically the document starts scrolling on mobile (tested on ios) ...
or am i confused?
setting preventDault for touchmove manually stopps the document from scroll when dragging ...
so i'm not totally wrong
bug or feature?
Unfortunately this is a bug in iOS 10. I've filed it with apple, and have a workaround in the Hype runtime for the next version.
In the mean time, the workaround you can use is to call event.preventDefault() in the On Mouse Down (touch start) event.