4k resolution video gets compressed to 900x800

. Hi so I own a S20 Galaxy FE, it has 4k video resolution and I've been getting an annoying issue when ever I save/export a video it reduces the copy to 720x900 and less than 25mb of file size. This is happening on both the mobile app Adobe Light room and the PC version Is there a way to tell the software to keep the original resolution? It's really annoying because then the video looks crappy