@skulas
Is it possible that you have another control in the foreground that is impacting that?
I would try (start with the back button) to bring that to the front...publish...refresh mobile and see if there is still an issue.
Also...is this happening on all apps and all devices?
1) throw together a very simple and quick app to test. Put a button on the left and some action on it. Then test on the device.
2) try another device to see if the issue is there as well.
In general, I've never experienced any issue like that which didn't fall into the issue of some other control in the foreground.
I hope this is helpful to getting to your answer.