Scroll freezed on Ipad on Safari (iOS 13.3.1)

[bgrenier]

We are using ViewerJS for displaying pdf files in our application.
It works well on Desktop on IE and Firefox but we have a problem on Safari with an Ipad (iOS 13.3.1).
The document is correctly displayed but user is unable to scroll the document. It sounds like freezed.

We found a workaround to re-active the scroll, it is to click on zoom in/out button.

Did you already get this behavior and do you have any idea to fix it ?