Found something which may be a Bug, if you take a Group of Fixtures and you want to arrange them as a circle, works well. One glitch I found is when You arrange them in XZ Mode, and then choose to Rotate them to Circle Center, in this XZ Mode they will rotate well on the right side of the Circle (if looked from the top), but the right side is shifted to the left (if you take the bottom of the circle as a reference) instead to the right; cf Screenshot (taken from 2D Front).
In XY it is fine if You look from the top. In XZ Mode they all look down (if looked from the Side)
Cannot recall how it was on GMA2 however