Good luck tracking this one down: I just matched four red gems and three brown gems, and my Alchemist received six mana. By my count, he should receive at least eight, before banners, and at bare minimum seven (if I were foolishly using a -1 red or -1 brown banner). This was the first turn of the battle, so there is no way I lost anything in a cascade animation.
God, I wish iOS had a native video-recording option. I’ve had a couple of instances over the last week where a match-4 turned control over to the AI, but without video it’s hard to confirm that I didn’t accidentally switch the wrong gems in my motion.