@nico to understand why #github behaves in messed-up ways, look no further than its owner. Github is owned by #Microsoft - a truly disgusting company.

Abandon github and move to for example Codeberg. Or really anything else, just move far far away from anything Microsoft-related.

"nslookup github.com" --> only ipv4

"nslookup codeberg.org" --> both v4 and v6 as it should be.