I know you are much more experienced that I am, but I have read that younger males are generally a little more inexperienced, so that could be a problem. I have one of my younger males that would always try to mate with the females, whether in heat or not. None of the females wanted anything to do with him, I am assuming because of that. I would think that if something like that is going on, the females might just be turned off by him. I would maybe try to put a different male in the run, and just try to pair him with one female that seems to take to his company. Once I put him with a younger female who was just as inexperienced, everything worked out. But you did say one of the females wasn't proven either. I read a few places that if they haven't mated in a year, then switch them, but I think that is a bit extensive because I have yet to see a problem lasting that long. Good luck!!!
