Larian Studios Forums Divinity - Original Sin Divinity Original Sin - Help/Tips/Tricks Action Points and how it is calculated?

Something is very wrong here but I have no idea what.
Constitution has no effect on TURN AP in my game.
However, I do not receive TURN AP at a rate of Speed/2. For example, I get a boost at 7 speed, but not 8 Speed or 9 Speed.
START AP seems to be working correctly using 1/2 Per + 1/2 Speed. So is MAX AP, at a rate of 1/Con.

I read somewhere that TURN AP is granted at Base + (Speed * 0.33) rounded down. Therefore you should get a boost at 7, 10, 13, 16 Speed.