Actually it might be whitespace in "username" (which is actually profile.name field) that breaks it
Discussion
I just tried setting display_name to blank and put whitespace in my name field and nothing seems broken to me. What do you mean by breaks it?
Sorry for the vague bug report. Actually the issue was: when I logged in using my public key, it would pull some old relay list of mine that doesn't connect (1 relay requires auth and 1 doesn't exist anymore).

But also I noticed the app froze when you add a space to username, i.e. nav buttons and the form stop working:
