I had to clear my cookies last night, so I had to log back into the site this morning. I have never used anything other than my username to log in on mobile or desktop, but today I got a message that “The requested user Stasia t’Andrei could not be found”. After telling myself to not panic, I tried various combinations of typing it, filling it from LastPass (which I normally do), using all caps or not, etc. None worked. Switched to my email address instead and it worked, taking me to the two-factor verification page where it said “Logging in as Stasia t’Andrei”. Not sure what the deal was but I figured I’d report it, since this is a new occurrence for me. I’m using Safari on iOS 12.1 if it matters.