Hi Hunter,
When you set the second pupil, did you listen in the conference to see if it behaved like the first -- i.e. can both pupils hear the coach?
I'm not sure, but it makes sense to me that we might allow for only a single coach, but permit multiple pupils.
Let me know if the 2nd party set to pupil is working just the same as the first. And also check to see if the original pupil is still working normally after setting the second.