That's the problem, I think that Graal Classic has this same kind of protection to their servers or something.. Since we can't enter the captcha whilst entering Classic we're left with a black screen or a disconnection.

Using a VPN works for me, and when you use your HotSpot (Mobile Data) it has a different IP from the others.. I think.. It's a problem with your ISP, I never gotten CloudFlare once I moved and changed ISPs.