To prevent scrolling on modern mobile browsers you need to add the passive: false. I had been pulling my hair out getting this to work until I found this solution. I have only found this mentioned in one other place on the internet.
function preventDefault(e){_x000D_
e.preventDefault();_x000D_
}_x000D_
_x000D_
function disableScroll(){_x000D_
document.body.addEventListener('touchmove', preventDefault, { passive: false });_x000D_
}_x000D_
function enableScroll(){_x000D_
document.body.removeEventListener('touchmove', preventDefault);_x000D_
}
_x000D_