When a TSO session is opened on the SOLVE:Access MAI main menu, it is possible to retrieve the session from another terminal without any problem.
This is not possible with a CICS session, Why?
We are dealing with a limitation of the application.
With TSO, having created a session from an MAI session list, it is possible to go to another MAI session and reconnect to it. With a logon script the reason is not clear, but in the TSO logon panel there's a "Reconnect" field and the default is "S" to reconnect. If this is blanked out, it returns the same error as CICS - already logged on.
With SOLVE or NetMaster, it is not possible to reconnect to an existing session unless it is first disconnected e.g. via a "DISC" command.
The only way to return to a CICS session from a different terminal is to disconnect the MAI session (at CA that's ".DISC" and F12 in the application, or just DISC if in an MAI panel).
Then logon from another terminal, accept the offer to reconnect and then it is possible to return to the CICS session.
So without doing a disconnect from the SOLVE:Access side, transfer is driven from application side, so in this case, customer would need to clarify with IBM whether a reconnect option is available for CICS.