User is logged on to a temporary profile

Hi All, 

A virtual server (with Terminal Server role) based on Windows Server 2016 was upgraded several times in attempts to rectify the issue with users logging on to temp profiles. The number of connected users roughly 30-35.

It now has 20vCPUs and 72GB or RAM and at the moment CPU usage is about 30% and RAM usage is about 70%. This means the server is not running out of resources.

Now that I can exclude the resources related factor what else might be the root cause of this issue which recur literally every day?

Regards