When I select an ability to use, the vampire action says it's using an ability, but within a split second that disappears, the ability does *not* trigger, and the ability icon is grayed out. This didn't happen early on in the game, but does happen now that I'm in a few years and have near maxed-out vampires. This is extremely inconvenient since I use them as my main raid attack/defense force and now they've lost a lot of their combat potency :/