Ok so I set up to record a specific area on my second screen, I was trying to record a live streambut as I say on my second screen the area selected was shown as red and was in the right place on the screen and at no point did what was inside that box change.
However when i tried to view it back although the sound was captured fine the image what what ever I was looking at on my first screen. It still captured the correct size but not the area I had it sat over the top of.
I hope that makes sense If you need more info please let me know and I will be happy to post it.