Rendering to a 2d canvas while XR mode enabled

I am trying to take a screenshot of the player's current camera view. I'm using the following code:

document.querySelector('a-scene').components.screenshot.capture('perspective')

It works in normal mode but when entering VR mode it doesn't work. It still saves the same image and ignores what VR camera looking at. Because as soon as it enters VR mode, it stops rendering the canvas, either freezes or turns black. Here's my scene:

<a-scene>
<a-sky src="puydesancy.jpg" rotation="0 -130 0"></a-sky>
<a-text font="kelsonsans" value="Puy de Sancy, France" width="6" position="-2.5 0.25 -1.5" rotation="0 15 0"></a-text>
</a-scene>

how to keep rendering inline canvas while on vr.

• A-Frame Version: 1.2.0
• Platform / Device: web

Reproduce the issue with the provided A-Frame scene and the components.screenshot.capture('perspective') entry point, first comparing normal mode with XR mode. Trace why the inline canvas freezes or turns black in VR, and consider the work complete when it continues rendering the current VR camera view while the screenshot is captured.