Summoners War: Chronicles

2nd time this has happened, only similar point being me spamming water Unicorn soul link, 1st time it at least gave me one eventually, thought it might just be a visual bug and really slow ultimate, but no, not a visual bug since I tried using an ultimate when it was that high after using a 5 mana cost skill, no way it wouldn't be full. Doesn't happen the majority of other times I used water Unicorn, and the 1st didn't happen until half way into the match, happening after an ultimate at 0 again, refreshing to that high number eventually but then gave me one.