OK I have some screenshots that basically represent what is happening on all of these devices. It is more or less the same thing across all of them with varying degrees of how far one can scroll down.
This is as far down as I can scroll on this devices. A Nexus 7, not very far. Maybe we can break the barrier another way.
I have noticed that sometimes some things can happen with this off canvas menu. Lets see if it can help us out.
Jackpot. I was able to break the lower boundary it was stuck at by going around. But why does the area below the top area look dark?
This is as far as I can zoom out on this device. I also can't go any lower. Using the menu > swipe down trick I was only able to look this far down the page. My own installations of this theme have the same problem, but only if a video is elected to show.
To test a theory. I made a change to the lower sample sidebar module that is within the menu. Well I removed it. It shouldn't have any effect right? But it had a minor effect that changed how far I could go down the page (a little further), even without the menu actually being open. Where before I could just see a small white line, I could actually make out most of what was in the row below it.
Once again, clearing the video text field solves this problem entirely. Clearly something is left over.
I would look for some strange interaction between the sidebar menu, and the video element. I know it isnt specific to these devices because, well none of these devices have anything in common. Some are stock android, one isnt, another one is Sony made but does not have the problem.
EDIT: Trying to not kill you with image size. Fooling around with the BB Code.