Good find!! I tested a bit more:
Brave → no connect
Librewolf → no connect
Opera → no connect
Mullvad → no connect
Firefox → connect, but with a long delay
Netsurf → immediate connection without delay
Falcon → immediate connection without delay
It looks like they block privacy oriented browsers. It looks a lot like this:
Understandable but in my opinion the wrong pavlovian reaction.
This is bad news for privacy.
This could cost them a lot of community trust.
(by the way, no problems here whatsoever with cloudflare)