Two finger zoom-in pinch does not work and causes tab list to show up

I’m also affected by this issue

When working on this, please also consider this example: Visit

https://storymaps.arcgis.com/stories/36a7f6a6f5a9448496de641cf64bd375

Scroll down to the map near the bottom of the map. Using a two finger spread, you can zoom in on the map. (You may prefer to remove the legend menu using its close box first.) And in the other direction, you can zoom out using the two finger pinch. But if you take it too far, you activate the Tab View Sidebar or Grid, which is not desirable at this point.

What I think distinguishes this from the example given, is that the web page actually recognises and acts on the gesture. And when it does, perhaps the browser at large should not act on it. (But I won't rule out the possibility that the map here is programmed wrong. Should the javascript handling the pinch do something to stop the event from propagating up? Can it do so? Is that question even relevant, or does the browser just interpret the pinch independently of what the page is doing?)