"Different attachment facilities cannot be active concurrently within the same address space. Specifically, the following requirements exist: An application must not use CAF or RRSAF in an CICS or IMS address space. An application that runs in an address space that has a CAF connection to Db2 cannot connect to Db2 by using RRSAF. An application that runs in an address space that has an RRSAF connection to Db2 cannot connect to Db2 by using CAF. An application cannot invoke the z/OS AXSET macro after executing the CAF CONNECT call and before executing the CAF DISCONNECT call."
So, in this case the IBM DB2 Admin tool is using a CAF connection. The Db2 connection type, CONNECT(AUTO) is the parameter option that enables the CA Database Management Solutions for DB2 for z/OS to switch to RRSAF as required.
As the Db2 Admin Tool is using CAF and CA Batch Processor is using RRSAF, the problem of simultaneous accesses (CAF and RRSAF) is the reason for the PTIDB2-CAF.
When the user has CONNECT (AUTO) in SETUPxx and does not have a split screen(no other application running) the ISQL / Batch processor does not have a problem with the RRSAF setting being used.