Hey guys - love the game, I'm meant to be studying but I'm playing shadow era online instead .. Oops!

I've been playing my elements deck - but fir the last few matches elementis's 'sacrifice ally' hasn't been working even though I have enough shadow power to use it?

I'm on a gen 1 iPad ... It was working earlier today but seems to have decided to not work any more even when I reloadnthe deck.

The ability on my undead hunter works though?

Any ideas on elementis's ability not working at the moment on iPad? Thank you