Problem with logging in to cPanel created with WHMCS

I am using WHMCS v5.2.7.

I have created and accepted an order and had it created through WHMCS. The problem I am having is that neither I nor my client can log in to the cPanel with the username and password created.

I see the account in my WHM, and even had the site active using my cPanel credentials.

Also, the only link I see for getting to the cPanel through the client area is in Portal Home > Client Area > My Products & Services > Product Details.

Can anyone tell me what I have done wrong?

EDIT: I have been able to sign in to the client's cPanel if I go directly to the login page without going through WHMCS.