I am working as an editor for someone and am signed in on their account to access their Premiere Pro subscription. However, Creative Cloud tells me that I don't have access to it, and only allows me to start a free trial. I have tried restarting Creative Cloud, restarting my computer, repairing Creative Cloud and uninstalling it. None have worked.
There could be a couple of reasons for this. The one that leaps immediately to mind is that you will be signed in on a totally different IP address (which will raise a big red flag at Adobe Towers, I suspect) or else the alternative is that they have already used both available usage slots (although if this were the case it should tell you that you have no activations left, or similar).