Auras which have an active energy cost cancel when you don’t have sufficient energy and have to be recast again when you do which is usually a second later.
I keep aura buffs on the secondary toolbar because I should only have to cast them once a game. That means I have to swap to the second toolbar and back and much worse in a multiplayer game I can’t always tell if I have my aura or someone else’s so if I think I might have run out of energy in heat of battle I have to go stand in a corner away from other players to see if my auras need to be recast.
Auras should just stop providing the buff when you can’t pay the energy cost, not cancel and need to be recast.