Chrome DevTools Mobile Emulation scroll not working
When it happened to me, I closed the tab and launched again. It fixed it.
I had a similar problem when running Chrome on MacOS. If you know a device width let's say iPad is 768px width then instead of device choose Responsive and enter 768px for width. After that you should be able to scroll.
In the past I have found touch events to be flaky in chrome dev tools. Turning "Emulate touch screen" off and on again often fixes the problem for me. The page you sent works fine for me on current chrome in mobile emulation mode.