I've just hit the IPv6 problem. I routinely use yt-dlp -6 to cycle through my (basically infinite) set of IPv6 addresses. However when you do this, it tries the github EJS download over IPv6, which fails as github doesn't support IPv6 (because it's still the year 2000 over there).

Actually I think this is kind of a yt-dlp bug, since it doesn't need to use IPv6 for the github download.