It was impossible to access the forum with Tor for about 48 hours, I tried with various connection settings in Tor, but CF simply did not allow the captcha challenge to pass. Apparently the attack lasted a little longer than usual, but now everything is back to normal.
It's still not normal in my side. I am still using the VPN connection as I had no success from the TOR yet.
~snip~I don't know if a very small number of people use Tor on this forum (it seems so to me), because for two days the forum was inaccessible to me through the same thing, and you are the first to complain about it. It is possible that for some reason you still have problems, I don't have them at all anymore, and someone didn't even have them yesterday.
I don't know if it will have any effect, but if you haven't tried bridges, you can try under
Settings -> Connection -> Use bridges ON -> Select a bulit-in bridge