For ring of forgings, it will do this when the first ring breaks. But it won't for any other rings. the reason for this is the charge for your first ring may not line up to the trip count. If you dont want this to happen, break the ring to reset the counter.
As for getting stuck, its strange that it does this... it may just be a mirror mode thing, but where abouts does it stand still?
if this issue persists i'd suggest switching to a different furnace for the time being
~apa