Mana Flow Rune isn't working [EUW FIX ASAP]

yeah instead of giving a refund of the next ability and 8% of ur missing mana, it now gives you +25 total mana every time you hit an enemy champ, stacking up to 10 times at 250 extra mana, then at at 10 stacks it also regenerates 1% of ur missing mana every 5 seconds.

So not only does it give MUCH more mana in early game but the total amount of mana regen per minute is now higher; 12% instead of the previous 8%

Maybe you should read the patch notes before assuming.