I'm having the same fel hunter issue. The first two runs it worked fine, there was no green target indicating move command was ready, so I spam clicked both times and he went. After those first runs, nothing. I've tried everything I can think of except a fresh install of hb(that's next), I'm using it as indicated with Tyrael and all. Been using hot key mode though, maybe I'll try automatic. Here's a log anyway.
Edit: It worked on automatic mode, but the RNG got me and one of the hunters free'd the pit lord anyway(after being agro'd on me); but he moved this time at least. Then the following two times nothing. I think it gets performance anxiety and collapses under the pressure... I will say this though, there's a big difference in the pit lords fight behavior from when I did this a couple months back. He positions himself to keep the target between the two of you nicely now, last toon I did this on I was running around trying to stay in his breath after movements. lol