System.Threading.Tasks.TaskCanceledException: The request was canceled due to the configured HttpClient.Timeout of 15 seconds elapsing

when i enter the key in the keymaster i got " System.Threading.Tasks.TaskCanceledException: The request was canceled due to the configured HttpClient.Timeout of 15 seconds elapsing."

I got two different servers with the only difference beside ports, the server if we call it “server 1” got this error code.

“Server 2” Got more mods and is our DEV server so its very similar with Server 1.
Server 2 is also got on the serverlist without a problem.

Got the same ESX, CFG file and everything beside servername and ports.

How can i solve this?