Hi,
I just updated from Unity 5.4.4 to 5.6.0f3, and immediately noticed the rendering order of my GameScene cameras has broken…
I have a MainCamera, with depth 0, and 2 uGUI cameras with Canvases, depth 5, -2, and finally 2 NGUI cameras, their depths are irrelevant here.
The MainCamera ViewPort is 0,0,0.667, 1, but the uGUI cameras view ports are the same at 0,0,1,1. For some reason, the MainCamera is always rendering after both uGUI cameras, even though the depth should be between them.
Finally, I noticed if I change the view port of the top uGUI camera to something like 0.001,0,1,1, it works again!! Some batching is messing up the scene rendering order…
I already submitted a ticket with my project attached.