A CCI connection into z/OS failed to connect until another CCI connection had dropped. Since there was very little below the line storage available to CCI, once the storage was freed, the connection was established.
The bulk of the storage appears to be LE related possibly due to the Language Environment storage options in use.
Use IBM’s RPTSTG option to review the LE storage options currently in effect and make the necessary option changes to achieve more efficient use of your "below the line" storage.
The RPTSTG option is found in the z/OS Language Environment Programming Reference.
The Language Environment storage options themselves are found in the z/OS Language Environment Programming Guide.