I'm working on a little mod that occasionally adds an ability to the player with Fortify Agility. Since agility contributes to fatigue, I'm also trying to add a Drain Agility effect with the same magnitude. The problem is that whenever this ability is applied, the interface shows 65369/65369 (or something similar) and the fatigue bar appears maxed out. When the ability is removed, both displays go back to normal.

Is there a way to fix this? Should I do this another way?