Ok so this have been driving me CRAZY.
First, I was trying to render out a simple Render Layer (2020 version) for compositing of an object.
I constantly got NOTHING on render (blank .png/ or black photoshop file).
While in the LV, the render I was getting was looking exactly how I wanted.
I disabbled "overwrite kernal settings" and still nothing. Then, finally after some tweaking, I got it to work, BUT it was like lights cast no shadows (diffuse channel only). This was not enabled.
So I updated to the latest 2021.1-R2.
Tried with that.
Now my render is super bright, like the diffuse is bumped WAY up, much more than that with AOV/ render pass disabled.
So I did a test with some basic cubes - see attached.
Whats weird, is that it doesnt matter what I do, the second I hit enable on render AOV group - my render comes out all jacked up.