My Mavic was a refurbished drone & I was wondering if there was a problem with my camera as well. My, relatively, inexpensive P3 standard takes much better pictures & videos straight out of the camera. I don't want to & frankly should not have to spend time & money in post to get a passable image. My pocket camera takes better video than my Mavic & requires no or very minor post production.
Since getting the Mavic, I literally have pages & pages of notes & spreadsheets with every conceivable combination of setting, & still have substandard videos. I love my Mavic, my favorite toy. It is a great drone with(in my experience) a less than great camera.
I'm afraid that you have a defective camera.