So I tried rotating the tablet into portrait mode as suggested, and the buttons suddenly work!
I'm not sure where the bug lies in this case, but wherever the bug is, the version of xmir that is currently in the overlay is not affected by it whereas the overlay candidate is.
Update:
So I tried rotating the tablet into portrait mode as suggested, and the buttons suddenly work!
I'm not sure where the bug lies in this case, but wherever the bug is, the version of xmir that is currently in the overlay is not affected by it whereas the overlay candidate is.