[QuickSilver]

I think if he was getting it before, just go back to your original moves and he'll pick it up again quickly. Thor has known Bang for a while, but only in one very specific spot in the living room. Anywhere else, and he would just Down. We're working on getting him to be more flexible about it.

I taught Thor Roll Over first (which took FOREVER), and then Bang. So you could try that too. I remember when I thought he would never get Roll Over, but he can do it in his sleep now.