he has probably add an indirection level : now, the message receiver is not the user message queue but an intermediate program. And this program don’t take care about promoting a completion message. not strange.
The SBMJOB command will return a CPC1221 message to the program that runs the command. From a system menu, the program may be QCMD. In PDM, it’ll be QUOMAIN or however PDM does it. It’s up to the program to decide what to do with messages that arrive on the program’s message queue.
Display file message subfiles are often used to display messages from the program’s message queue. Some source related to the message subfile and the handling of the program’s message queue would be useful.