Why do animation montages seem to play at different rates?

When I press a button to do an aerial attack on my character, sometimes the transition animation montage will play at the expected speed (about 1/3rd of a second), but often it will play much faster, almost as if the animation is being skipped.

Is there a setting in the state machine that causes this? I don’t think any other montages are playing over or competing with the initial transition.

It looks like it was being caused by the stop anim montage node, which i was applying too liberally within the character controller.