Galio and Athene's passive working as intended or bug?

During my 1 for all game we got galio, and of course built Athene's but found out that Athene's passive wasnt procing on Galios shield, is this working as intended? if it is that's a bit ridiculous considering how much of a staple it is on Galio, plus why not give Galio a slight buff? Edit: does anyone know if there is any idea if this will get changed in the future?