If its an actual android box there shoud be a factory reset button inside the headphone jack, just push something like a blunt cocktail stick into it until you feel the button click and hod it down for about 30 seconds 👌

https://www.mibox4.com/how-to-hard-reset-xiaomi-mi-box-s-without-remote/

I had this happen with my Nvidia shield recently, stuck on this loading screen. I had to factory reset it, and it has worked since that point.