When I need to debug a CL program, I don't use the Start Debug (STRDBG) command. Instead, I enter the following command to force the commands in the program to be recorded in the job log.
After executing the program, I use the Display Job Log (DSPJOBLOG) command to check each command and parameter.
If this technique doesn't provide enough information, I insert the Dump CL Program (DMPCLPGM) command into the program. I recompile and run the program again; then I display the QPPGMDMP spooled file so that I can see all the variables used in the program.