Works for me.
Discussion
Works on Damus iOS and Nostrudel (Web). Not sure why Amethyst thinks it’s invalid.
Valid for me in Amethyst
So weird!
Other nip05s work for me.
I don't think whatever problem you're having is related to Amethyst because I and several other Amethyst users have no problems with their NIP-05. Perhaps it's something related to your connectivity to BitKey?
Works for me on Amethyst