when i attacked a planet with 0 defense and 0 attack i hit for 18 damage, i then alerted it to the legion and looked back to see if i could do some more damage to find oh, my attack didnt go through, but it took my energy, then just about 20 minutes ago i took a different planet SAME THING, im not petty so im not gonna demand 10 energy back, but thats a lot of energy to a new player.

I think what you're talking about has been happening to me too, where the second attack for whatever reason doesn't work. I don't know why it happens, and it's really weird, because after that the attacks will work, it's only the second attack that doesn't, and not even every time.