Neither I nor theymos know why I was stuck seeing "Sorry, you have been blocked" long after it was fixed for everyone else, nor why it seems to be fixed now.
I've seen that message too, and I
still get that message when I use Shift-reload (a hard reload) in Firefox. When I do the same in Chromium, everything works fine.
My guess is that a hard reload doesn't cache anything, and somehow Cloudflare doesn't like that. Could it be you've disabled all browser caching?