Why has this been happening the last month or so?
What just happened now:
I had 110 energy left. I attacked a mob for 60 energy and killed it in one hit. I then had 9 energy remaining. Why? What the plant? I should have had 50 left.
So I close the game down, restart my ipad and when I get back into the game I have 22 energy. First of all, I don't regenerate nearly that fast. I was out of the game about 60 seconds so I should have gained a single tick of energy, perhaps two if we're being cautious. I regenerate 4 energy per tick and my guild has +10% faster regen. At most I should have gained 8 energy and been at 17. Even if I gained an extra tick that would have put me at 21, not 22. In fact, if I have 9 energy at any time it will be impossible for me to ever gain energy up to 22. I will gain to 21 and then to 25 afterward.
These random gains and losses are more Gree butter.
Edit:
Leaving the game closed for 9 or 10 minutes and now I have 89 energy. Figure that one out.