[CLIENT] Cant buy hextech mystery champion shard

It happens when i start a game at 16__ ip and need one more game to reach 1700ip to buy a Champion shard. And after i finish a game, finally reaching 1700 ip, i click on the store and attempt to buy the hextech mystery champ shard. However, when i press on it still says "not enough RP/IP". This started about around maybe the last patch before 6.15. And it has occurred every time and i fix it by refreshing my league of legends client every time. STEPS: 1. I finish a game and reach 1700 ip. 2. right after i finish the game, i quickly head to the store to buy the Champion Shard 3. i click on the icon of the champion shard 4. i cant press "1700" under influence points casue it still says i dont have enough ip to buy it.