I've got the problem with recorded videos and GIFs using ReLive.
I have 3 monitors of 5:4 ratio, but each of them is rotated by 90 degrees, so the panel is 12:5. When I save a record, it also is saved rotated and with lowered resolution.
As an example, here is a frame of an instant replay (couldn't upload a video). Instead of 3072x1280 it has 1920x800.
Screenshots also are saved rotated, but they don't loose quality and can be rotated from the context menu.