Last night it appeared WHMCS had fixed my issue but today I am encountering the same. I believe now the problem is that, since I'm using a cloud hosting service, the ip isn't static rather it changes often on a day to day basis. Months ago WHMCS was able to resolve this issue for me by doing something that I really do not remember at this time because I am unable to access my WHMCS admin to retrieve my old tickets. Can anyone help??!!!