For Act! v18.2+, Act! corporate changed the licensing software component.   If you add or remove users from your initial purchase, we have seen the user count on workstations not reflect the update properly.

So, it’s a best practice on each workstation and the server to manually refresh the activation count.  The screenshot below shows you how it’s done.  The database doesn’t have to be open.  Once you refresh the activation, restart the program to see the updated count.