I have had this problem for years. When i try connecting to ucraft using my home internet (fiber optics cable) it gives me this error.

"Unable to connect

Firefox can’t establish a connection to the server at accounts.ucraft.site."

This persists whether I use firefox, chrome, or edge.

But when I connect using mobile phone data, or have a VPN running on my desktop, it allows me to connect.

So ucraft has some issue with my IP address