bitpunk.fm seems to have a different server setup that ignores the parameter part after nostr.json and always returns all the users
eg
https://bitpunk.fm/.well-known/nostr.json?name=bearetta
https://bitpunk.fm/.well-known/nostr.json?name=Bearetta
https://bitpunk.fm/.well-known/nostr.json
all returns the same list
i do the same for x0f.org actually--there's so few users that there's no reason to implement database lookup logic
for bigger servers, or if they want to make it more difficult to enumerate users (for privacy), it makes sense to do so, and minestr.app apparently does