IP not adding up [CLIENT]

I've noticed this since the last update that my IP isn't showing the correct amount on the client. For example: it will say I have 47 IP when I first sign in and then I play a couple matches and then it says I have 527 IP. But when I sign out and sign back in to the client I'm suddenly only at 370 IP. There have been multiple times I've attempted to buy a couple runes but been told I've been short. I'm not sure if the IP just isn't adding properly or I'm actually losing IP points somewhere, but it's been happening every time I play since the last update.