Intertest Breakpoints for Cobol programs are working fine. However for programs with API codes it is jumping from different statements (not on the next line as expected).
Z/OS with API
The programs were compiled twice, in two steps: one compilation produced the executable module, the purpose of the other was to produce the compilation listing which was then stored in PROTSYM.
Because the outputs of these two steps were not perfectly in sync (compiled program from one step, and the listing from the other), Intertest couldn't determine the correct location within the program while debugging.
Eliminating the additional compilation step resolved the reported issue.