It's been happening to 4K now too. I have some yt-dlp copies of videos that I grabbed a couple years ago. If I go and download them again today from the same

It's been happening to 4K now too. I have some yt-dlp copies of videos that I grabbed a couple years ago. If I go and download them again today from the same video URL, the quality is worse when I compare frames from them directly to each other.