No touch screen scrolling in some browsers

I’ve noticed that on a touch screen laptop running Windows 8.1 scrolling up and down the page doesn’t work in IE11 or Firefox (try touching an inactive part of the screen and dragging up and down – nothing happens). It does work correctly in Chrome.

Tested with my site https://go-reading.org – have tried with a couple of other sites using the same theme and see the same phenomenonon, so this seems to be general. Any ideas?

Thanks!

David.