Each workspace has its own address, <workspace>.sysj.com, and its own identity realm. A sign-in to one workspace is never valid in another.
If you do not remember the address, use Sign in on sysj.com and type the workspace name; you will be taken there. The page does not check whether the workspace exists, so a mistyped name takes you to the address of a workspace that does not exist.
For help from inside the workspace, use Support in the console, which sends your message with the page you were on.