DFH5182 when running DFHCOMDS after adding DEFINE commands to JCL

Question

Why am I receiving unexpected messages like DFH5182 and DFH5102 after adding DEFINE commands to CICS job DFHCOMDS? I alter and run DFHISTAR with the appropriate installation information. The run of the job creates a generated DFHCOMDS job that is used to define a DFHCSD dataset using my high level qualifiers. I altered the generated DFHCOMDS job to add several DEFINE PROGRAM commands, just following the line containing the dataset name information for CEECCSDX. A LIST command was also added to a later step. The LIST command executes but the DEFINE commands are ignored. NOTE that without the LIST command added, there are no exceptions or messages produced. The DEFINE commands are simply ignored and not executed. Here is example JCL and messages produced with the LIST command added to help force messages:

        //         DD DISP=SHR,                                           @01C
         // DSN=DSN.SCEESAMP(CEECCSD)
         //        DD DISP=SHR,                                           @P6A
         // DSN=DSN.SCEESAMP(CEECCSDX)                                      @P6A
         //        DD *                                                   @01C
                   DEFINE PROGRAM(PROGRAM1) GROUP(MYGROUP)
                   DEFINE PROGRAM(PROGRAM2) GROUP(MYGROUP)
                   DEFINE PROGRAM(PROGRAM3) GROUP(MYGROUP)
          :
         .
         LIST  GROUP(MYGROUP)
         .        

These are the message that I'm getting:

    DFH5120 I PRIMARY CSD OPENED;  DDNAME: DFHCSD   - DSNAME:
    MY.CICSTS51.DFHCSD
    DFH5182 W GROUP MYGROUP DOES NOT EXIST.
    DFH5102 I WARNING MESSAGE(S) ISSUED WHILE PROCESSING LIST COMMAND.
    DFH5123 I PRIMARY CSD CLOSED;  DDNAME: DFHCSD   - DSNAME:
    MY.CICSTS51.DFHCSD