Follow Through, Blade Storm, Vengeance Strike, Double Tap, Riposte, First Strike all have this same problem:
These powers don't reset at the end of a fight. When I finish one fight and go right into another, sometimes these power don't activate because I had used them in the last round of the previous fight. I have had this happen for the last few months (follow through only after the update).
Recently I was in the dino dungeon in Xol Akmul. Quint, my pelican, finished a fight using vengeance strike and blade storm. The next fight he ran up to three bad guys using Charge, did NOT use vengeance on a raptor who hit him, and when he killed the next dino he did NOT use blade storm and went straight to glancing blow instead leaving the third dino alive who he normally would have killed with blade storm (or vengeance if that had activated).
I think this should be an easy fix. Just have our powers reset at the beginning (or end) of each fight to make sure we get their full activations just like they reset at the beginning of each round.