I am now actually losing agility rapidly even if just burdened, and gaining almost none while unburdened. My char is at 16 AGI. Aren't characters supposed to be able to go above 25 AGI even without ommel supplements?
Don't you have leprosy, or some other deletrious status effect? Leprosy would make you loose stat exp quite fast.
Yeah, you should be able to train past 20, especially when eg. running and unencumbered.