@olivierlambert Hello
Yes, the problem is on http://mirrors.xcp-ng.org/8/8.2/base/x86_64/repodata/repomd.xml, there is 302 Found to non-IPv6 urls

You can try with :

curl -IvL http://mirrors.xcp-ng.org/8/8.2/base/x86_64/repodata/repomd.xml

You will see the differents mirrors associated (Link), and some of them redirect to ipv4.

< Link: <https://xcpng-mirror.as208069.net/8/8.2/base/x86_64/repodata/repomd.xml>; rel=duplicate; pri=1; geo=fr Link: <https://xcpng-mirror.as208069.net/8/8.2/base/x86_64/repodata/repomd.xml>; rel=duplicate; pri=1; geo=fr < Link: <https://mirror.as50046.net/xcp-ng/8/8.2/base/x86_64/repodata/repomd.xml>; rel=duplicate; pri=2; geo=fr Link: <https://mirror.as50046.net/xcp-ng/8/8.2/base/x86_64/repodata/repomd.xml>; rel=duplicate; pri=2; geo=fr < Link: <https://mirror-xcpng.torontot.fr/8/8.2/base/x86_64/repodata/repomd.xml>; rel=duplicate; pri=3; geo=fr Link: <https://mirror-xcpng.torontot.fr/8/8.2/base/x86_64/repodata/repomd.xml>; rel=duplicate; pri=3; geo=fr < Link: <https://updates.xcp-ng.org/8/8.2/base/x86_64/repodata/repomd.xml>; rel=duplicate; pri=4; geo=fr Link: <https://updates.xcp-ng.org/8/8.2/base/x86_64/repodata/repomd.xml>; rel=duplicate; pri=4; geo=fr < Location: https://rg2-xcpng-mirror.reptigo.fr/8/8.2/base/x86_64/repodata/repomd.xml Location: https://rg2-xcpng-mirror.reptigo.fr/8/8.2/base/x86_64/repodata/repomd.xml ... couldn't connect to host at rg2-xcpng-mirror.reptigo.fr:443: Failed to connect to 45.152.69.252