If it's just a thing with the Android build, I'll drop it and move on for now , but was maybe hoping it was something stupid I was missing in the manual.
Here's the scene with no effects :
With Post Processing Stack enabled ( V2 - the one on GitHub now ) - I get what I presume would be the mask for the non-blurred area, however it's just completely black.
I'd initially thought it was something to do with other stack effects being applied ( like bloom / motion blur ) - however it persists when it's the only effect in the stack, and all others are deleted.
Thanks in advance for any advice ventured, I just wanted to hide the lesser detailed backdrops and give a sense of space, for when the cat is knocking things off the shelf.