OBS is blurry in Zoom

If I have a video source and even one image in my stream from OBS to zoom as a virtual camera, Zoom makes the image blurry unless the video is smaller than 640x320. I have maxxed all the settings I can in zoom and tested obs with other services so I don't think it's OBS. I've experimented with different size images and it doesn't matter, it seems to be some sort of optimization zoom is doing. It happens even when I'm just using zoom locally with no other participants. Is there anything else that I can do or is obs just not useful with zoom with larger video sources? Note: The size of the images doesn't matter as far as I can tell.