I am using the MIUI 11 Android 10 weekly dev build and I've been having this very strange bug that hasn't happened on the stock 9.0 ROM. On YouTube (I haven't tested this on other apps) HDR content has EXTREMELY dark colors. For example, when minimizing an HDR video, I can notice the colors on all of the thumbnails to be noticeably darker than before. When I close the video, the colors switch back to normal. I know this isn't normal, because colors can go so dark that I don't even know what I'm looking at. I could be looking at a forest and it's black. Also, in Austin Evan's iPhone X review that was in HDR, the colors were a lot brighter than they are now, not to mention I could actually see details unlike now. I'm hoping this bug will be fixed sometime soon.