There is no such thing as "cloud-based pro series".  The URL you provided is for Intuit Link, which is a client portal, not a tax software.

Is your problem with your clients' documents not showing in Intuit Link?  If you access your clients' documents in Intuit Link using the URL you provided, that tells me you're not using ProConnect Tax Online because Intuit Link is fully integrated into PTO and is accessible only from the drawer within PTO.  If you use PTO and log into Intuit Link directly, you won't have access to any of the documents or messages you trade with your clients.

If you are really using PTO, the correct PTO should be ito.intuit.com.