problems with live streaming using OBS

[triforcesamurai]

Im a new surface owner and i recently downloaded Open Broadcaster software to live stream my art sessions over twitch. The problem i am having is when i preview the stream only 25% (top left corner) of the screen is visible. The rest of the preview screen is black. I am using the monitor capture and twitches standard 16:9 ratio. Is anyone else live streaming from their surface? Have you dealt with this? What settings do i have wrong?

Model is SP3 256gb i5 if that helps any.