Thanks for taking the time to give us feedback - I see my nemesis (UIs in unity) is causing trouble once again... sorry about that!
To make those buttons work, you'd have to aim at them with your right hand (which might require getting it relatively close, and I'd suggest pointing from above, vertically) and I believe you can't be holding any items. Although the game is designed to be played while stationary, maybe taking a little step to the right can help interact with the buttons?