I am both a newbie to Android TV and generally pretty stupid, but my brand new Android box is putting out really quite stupendously bad images (especially vis-a-vis false contouring) and I'm hoping someone can kick me in the right direction. The model is an X96 Mate with 4gb of RAM and 32gb of ROM, and it is connected to an old hard drive array via USB 2.0, and to an Optoma HD 142x projector via generic HDMI. The display setting is 1080p / 50Hz. I have ruled out the projector, the cabling, the disc array, and the actual media file (by switching everything back to my laptop).
I don't know how to embed an image in an ask-reddit, but here is a link that will take you to a comparison shot, hosted by imagebb. The top part is what I'm getting from the android box, and the bottom part is what I'm getting from my laptop, with all the same cabling, source, peripherals and settings.
I would suspect this has something to do with the "color space" setting. While I'm not sure if a color space setting is on your device, it's under the advanced display settings on my Nvidia Shield. There's an option there to automatically match the display's color space settings. It's off by default, but turning it on made a huge world of difference, especially when viewing HDR content.