[GAMEPLAY] Mejais giving incorrect AP

Mejais soulstealer gives 20 AP + 8 ap per stack correct? Then why is it that when Mejais starts with 5 stacks (so 40 ap totalling to 60 ap) it only gives +40 ap total when bought? Rhetorical question, this is the bug that i have found. i would attach a sceenshot but i didnt think to grab one when i noticed it.