WHMCS server connection issue

[InFinitePro]

Hi,

I connected my server to the whmcs and once saved and went back to the servers page, I see that it's just loading and stats shows "Not available" and no other information like "cPanel Version:  Load Averages:  License Max # of Accounts:  Last Updated: ". It just shows my server name and then once I try to test it again it get stuck on "attempting to connect to server..." and doesn't do anything. IP address has been whitelisted. Am I missing any certain cpanel & WHM settings so that it's not getting any results.