I have done some more research and used build 2016.2972 this is what happens:
I am creating a 25x25 tile map using a 132x127 pixel 2kb image when I take a display.capture with captureOffscreenArea=true I get a black image.
If I take the same 25x25 and do a display.capture with captureOffscreenArea=false it works
Both methods work in the simulator but the display.capture does not work on my LG G3 using captureOffscreenArea=true.