Oculus Browser - full screen video controls getting in the way of immersive content

I have a problem with the z-index of the fullscreen video control bar in Oculus Browser, blocking my interactions with elements 'behind' it.

I am playing 360 videos in Oculus Browser in full screen and then selecting "360 video" from the dropdown menu in the video control bar, to see them in full wraparound view.

What I'm actually doing is presenting a web page in 360, using the Fullscreen API - not just a video file. 
https://developer.mozilla.org/en-US/docs/Web/API/Fullscreen_API
With the video filling the page, and some clickable hotspots overlaid on top of it.

The problem is that the video control bar (with Play button, skip forwards/back and Normal/180/360 and 2D/3D options) is sitting halfway between the viewer and the video and blocking any interactions behind it. All clicks anywhere on the screen just pull up the video control bar wherever you click.

What I need is for it to let me click the clickable elements behind the video control bar, but I can't.
The video control bar basically creates a kind of invisible forcefield halfway between my hands/controllers and the buttons overlaid on the video.

Is there anything I can do? Is there any documentation I've missed about developing for these immersive features in Oculus Browser?