Talking from my own experience with magnets with qBittorrent on Windows; for some reason magnets don't work for me sometimes. I recognize the issue from my own experience. Don't know what causes it but I think I've gotten it to work when I've downloaded the .torrent file (the other option besides magnet is to download .torrent file) and open that with the software. Then it finds all the metadata it needs and I can start downloading
Checked Arch Linux torrent distribution options from https://archlinux.org/download/#bittorrent-download , they have the "Torrent for 2026.05.01" option available.
Doesn't fix the issue beneath, probably for sure, but has gotten me through not having to find an alternate source for the file, or flipping through diagnosing all the things that could be wrong (there was a time I tried!!!)
Most of the time magnets work, but the times it doesn't I've made due with this