1. Create a job ("A") that does nothing.
2. Create another job ("B") that does nothing.
3. In B's configure page, click "Add post-build action", then click "Trigger parameterized build on other projects".
4. In "Projects to build", type "A".
5. (My build used parameters, so if the above doesn't reproduce the issue, add some parameters to A and add "Predefined parameters" and type "X=Y" for each X=a parameter you added.)
6. Repeat steps 2 through 5 two more times, so A will invoke B three times.
7. Run A.
A's console output should indicate that it started B three times, and each instance should be +1 from the previous.
A's console output indicates that it started B three times, but each instance number is the same.