I am encountering issues with buttons while working in SDK version 0.017.003.
It appears as though the problems tend to multiply each time I hit play on the build and go into VR for UX testing.
In this case, the first playthrough was fine. On the second playthrough, the buttons in the scene were unresponsive when touched and appeared behind the user.
Seen here: https://imgur.com/YCGQ8b1