I am doing something stupid, and just can't see it and hoping someone has better eyes than mine.  I have two Doctrine entities which extend another class using single class inheritance, but when retrieving the collection of either of the two child classes, I get the collection of the parent (i.e. combination of both child classes).  I've experimented with making the parent abstract and not including it in the discriminator map but no change.  In hopes to identifying my mistake, I created a new S