[cpk]

Possibly an anomaly. Are you getting it dealt to you as often as you should? If less often, that can cause skew.

You may not be playing them aggressively enough when they are unimproved. I made that mistake for a while after a period of "running bad." It caused me to "run worse." Or you may be too aggressive. In general if you have position you should continue to bet, but you should probably pull up on the river unless you are heads up and it looks like your opponent was on a draw. You should also raise on the flop as that will often get an unimproved AK to fold behind you.