Hello, I've tried to reproduce this on a Nexus 5X (6.0.1) and a Honor 5X (5.1.1) and was unsuccessful in my attempts. Do you have any addons installed that might be causing this to happen?
Sorry guys, I can't help much more because this happened a week ago and the code I was checking has since been removed, so I can't even verify if it's still reproducing. I can only tell you I have Firefox 51.0.3 and I do not have any user-installed addons. There was a large custom JS library loaded to handle device orientation changes, using: window.addEventListener("deviceorientation", handleOrientation, true); It was weird to me that when I rotated the device from portrait to landscape with our URL loaded, instead of changing the Firefox window to landscape mode, it opened Chrome, so I actually wasn't even able to view the page in landscape mode. This phone has Android 6.0.1 on it. If you can't reproduce it, I recommend scrutinizing everything related to that event because there is probably some kind of instability in there, unless the root cause was Android and not Firefox. If you made a test case that checked if the content was loaded as expected after orientation changes, it would catch the bug. Sorry I cant give you reliable reproduction steps. -Adam
I'm removing the nomination for now. If someone can reproduce, please renom.