I think it might actually be an issue with my json.
A space between the name and the key.
Which is funny, because I created this tool after I manually wrote the json, which is actually giving the correct json! ahahahah
Discussion
I think your guess is probably correct due to incorrect json. I have seen #[7] sucessfully set up his own NIP-05 using _@iefan.tech
One interesting thing is if you compare curl response your nostr.json and iefan's nostr.json then you will find the difference of content type. Iefan has additional atrribute charset=utf-8 .