I've got this exact same issue; I use the safe-area-inset values to make sure the bottom long white line doesn't overlap content that the user must always see. The bar doesn't disappear because the player needs to be interacting with the screen. In ios15+16 the safe-area-inset-bottom value is 21px. If I hide the address bar, this value becomes 0, and the white bar is blocking our content. If I tap the address bar to unhide, the page occasionally shifts behind the address bar until I scrollTo(0,1) and then in a timeout of at least 50ms scrollTo(0,0). The browser seems to be unaware that the page has scrolled up by 21 pixels, even checking the positioning. One of a handful of weird positioning / visibility issues in Safari at the moment :)

Typically I'd add some CSS to the body: touch-action:pan-y; We have to do a bunch of this to prevent webgames getting zoomed or in a position where they can't be zoomed back out again - though currently in landscape ios15 it doesn't seem to fully work as expected.

Is your ondblClick function something like: function myHandler(event) { //Your code here return false; //Stop the propagation } That should trigger event.preventDefault() and event.stopPropagation(); The return of an event handler specifies whether the default action should also happen.