It worked after I used the https urls. This: https://relay.ngit.dev/npub16a6kfxprxgazyhc9ym6pe3dqmw4ran4uk50gu23nt0ttdecsavxs3cflrw/stats.git
Discussion
Did you try the https URLs directly after the nostr one or did you come back to it a bit later?
I'm wondering whether it was a coincidence or whether the git plugin is less resilient when it comes to connectivity issues.