Charge up getting stuck?

[thisawesomeguyy]

So this happens in and outside dungeons randomly maybe a few times a run , there's no pattern to it either but when I charge a skill up it gets stuck and I have to tap it again for it to work , gets frustrating

http://tapatalk.imageshack.com/v2/14/11/15/9fbc84ad4efaf51a0cdc94086638c856.jpg