I was invited many months ago but I messed up the username. After investigating I realized that there's no way to fix it, and keybase staff says the only way is to delete the account and get re-invited [1].
I forgot to delete the account, but I did so now, so if you're still willing and would be so kind as to try again, I would greatly appreciate it! If not, no problem!
I tried again as you said, but it still complained. What I ended up doing was to send the invitation to your gmail address without the two dots (as it's an alias for your original address), and apparently it worked.
I also emailed you the invitation code they generated, from my personal email.
P.S. Great looking Hakyll site!