[Zubersoft]

I've reverted my device back to the stable channel, I'm testing with the same settings as you (as far as I can tell from the video), but I'm still not seeing the problem. So I'm going to need you to either share a library backup file, or capture all of the settings across library settings, display settings, the display mode dialog, and the page scaling dialog, and I will see if something is different between how we've configured the app (I'm using almost all the defaults except for changing the display mode to vertical scrolling to match you and switching the few settings under Display Settings to match what was shown in your video). 

If I'm still unable to reproduce the problem after this, then I will start to think you've modified some kind of setting in ChromeOS itself that is responsible for this issue, as I now have a completely clean device on the stable channel. You didn't modify any of the OS settings related to the gestures by chance, did you? On my device, I can't even bring that blue bar down at the top of the screen unless I have a mouse attached. If I drag down with my finger, it switches between apps.

Also, please try testing one of the devices without the protective case on it. Those can sometimes trigger odd gestures on devices, so I just want to rule that out as a possibility.

Thanks,
Mike