Extremely low crit rates

Well i thought it was just me but during a arena fight i noticed a major change in my critical rate after the update. I mentioned it on global and at least five other players also noticed this. I'm hoping that there's a bug and this isn't permanent. Its as if my precision masteries aren't working at all. Theres a few champs that really rely on crit rates to be effective. Im wondering if this can be looked into before it becomes permanent.