my problem is that it is not issuing a cookie or a session when you try login into the manager
I wonder what the problem could be? I did change session_handler_class = modSessionHandler to MODX\Revolution\modSessionHandler but still same issue. could it be an issue with the server ie apache? its on the clients host I dont have access to it.
Have you tried deleting all files in the core/cache/ directory manually, then visiting the site with your browser in private or incognito mode? There might be a cookie or session left over from the previous version that’s causing trouble.