TFT GAMEPLAY BUG - Seraph's Embrace

Has anyone else noticed not refunding mana after cast? Just lost a game because of it. Had two on a LV 3 and after cast it wasn't boosting his mana at all. Not sure if it was working with just one. Unfortunately I don't have any video or picture proof but it should be very easy to recreate. Also not sure if it is specific or a bug with the item in general.