[GAMEPLAY] Kayle Fervor of battle bug?

Kayle gains fervor of battle stacks at a rate of 3-1-3-1 while her Righteous Fury(her e ability) is active, seems like a rather odd stack rate, considering she's a ranged champion at the time and its not stacking at a 1 per or 2-per so seems perhaps not working as intended

Note: after additional testing it seems that there's some sort of predetermined stacking order so some players may find it as 1-3-1-3