"Mirror Main Camera" prevents UI from rendering properly

[hpham]

This camera seems to be rendering on top of the main one when the poly spatial editor preview is enabled in editor. For some reason, this same behavior also happens in the simulator even though the editor preview shouldn’t be active.

Here are images of what the UI looks like before and after disabling the mirror camera.

[hpham]

I just submitted a bug report (IN-58134) for this. The easiest way to repro is by having a layout group containing three buttons with a behavior that sets itself as the last sibling. The results looks like the following: