Charge Move not executed

Sometimes the animation doesn't work properly, but it still does damage.

Mine was acting funny earlier. It would take 3 or 4 efforts for it to work.
I put it down to user error until I saw your question.

There are some posible answers to this, the ones that come to my mind right now are:

• If you dodge an enemy attack and the games thinks you have take the damage it will fill your charge move and when you try to use it it won't actually do the charge move because the game catches up and realizes that the previous damage was not taken and your charge move is not actually ready to be used.
• Just some kind of missclick, the same that happens sometimes when you actually swipe but the touch screen does not work as intended, so probably the game just thought you made a quick attack instead of a charge one.
• Your bar was actually full and you use the charge move but the game skips the animation (the damage is still done).

In your particular case I think the last one is the answer, keep an eye at the enemy health and try to see if it actually drops when you use the charge move.