The exitcode range is different depends on the operating system, while for UNIX, it's 0-255. If the UNIX JOB has return code -1, the system will translate -1 to 255 and inform the agent. And in agentparm.txt, there is a parm noexitcode which has the default value of 255, so the agent won't send the exit code 255 to mainframe. Then on CSF, these JOBs show as "Executing" even they failed on the UNIX server already.
If there are JOBs have return code -1, you can change the noexitcode to 256(or other value that never be used) and recycle your agent, then you will see CC 255 on CSF for the JOBs that have return code -1.
This Frequently Asked Question applies to all supported releases of ESP Workload Manager.