CA JMR does not display the SYSTEM ID in the ISPF panels display for started tasks only. This started only after my z/OS 2.1 upgrade.
The SYSTEM ID is provided to the display in the ISPF panel for CA JMR from the actual spooled output in the DAILY file. The option in PK46OPTN is called SYSTEM=
The default is SYSTEM=47
IBM has moved the word SYSTEM to a different offset in the output. The new value should be:
Once you change this value in the PK46OPTN you should recycle CA JMR to activate the new option.
See CA JMR Getting Started Guide section 5-25 to review the documentation for this option setting.