Crankcase pressure
At wide open throttle (WOT) you have no vacuum that is why your pcv valve doesn't not work. Theres nothing wrong with your car it's just simple physics. If you will notice drag car motors do not use a pcv valve because of this problem of no vacuum at WOT. They use breathers in both valve covers with valves in the headers. The exhaust passing by the valve in the header creates vacuum which draws out the positive pressure in the crank case. This will not work on the street because of the back pressure of closed exhaust. There are belt driven vacuum pump systems that can be purchased that will work for a street application. These work much better than the header systems and are the best thing going right now. It will set you back about $500 to $600 though.