As a Sentinel I got two moves: Opportune Strike and Pommel Strike. These can be used on immobilized (and slowed) and incapacitated targets respectively. Initially I was able to use Pommel Strike on droids I had disabled, but that no longer seems to be the case. As well one of them lights up when I'm holding an enemy still with Force Stasis, but I can't actually use it since the moment I click it the enemy is no longer held and it fails. This is all pretty confusing.
When can I actually use these moves? In other words, what's the difference between "immobilized" and "incapacitated" and how do I put enemies into those states?