[GAMEPLAY] Archangels staff doesnt give ap based on mana

I bought Archangels staff while i was dead from needlessly large rod and a fully stacked tear as cassiopeia. It should have given me 100 ap, 20 ap because it gives 80 and and needlessly only 60 and about 80 ap from the passive. Because i wanted to know how much it would give me i was looking at my ap and only got 20 ap.