Perhaps because Nostr turns your npub text from your clearsigned proof file at https://untraceabledigitaldissident.com/about/ into "@GHOST", verifying this text from here as displayed produces this error... 
Discussion
Well isn't that a pain in the butt. I love when software tries to "help" you without you asking it to.
Corrected on both the About page and new signed event.
Thank you for pointing it out, although this does show the flexability of the system that updates can happen quickly.