[Gameplay] Manaflow Band on Sion
Noticed it every time I try to play AP Sion, partway through stacking Manaflow band it stops going on cooldown preemptively and will no longer increase max mana, meaning you never get the mana regen aspect. When it happens the cooldown/ready indicator disappears entirely, and you stop gaining mana from spell hits. I even checked much later in the game to see if the display was just broken, but even 30 minutes into the second game I was not gaining extra mana from it.
First noticed it in a custom game I was in with my friend teaching him the basics where it stopped stacking at 225 max mana increase, it happened again last game in a normal draft 5-stack at 100 mana added. Not sure if this is just an issue with Sion due to his E's minion pushing since that's the major spell I'm hitting to stack it, but I haven't noticed a problem on any other champions the few other times I've used it.