Unable to register and attach the subscription to CloudForms appliance

Issue

• When tring to subscribe an appliance, the system shows "attaching subscription" but it never ends.
• The rhsm.log doesn't show anything, nor does the message.log
• The CloudForms service has been stopped and everything in the subscription.manager cache has been cleaned.
• Manual regestraion has been tried, and this also did not work.
  • The appliance registered, but the webUI did not reflect this change.
• NOTE: There is no proxy, these are direct connection to internet from the appliance.