In normal operation, the PCV system vents crankcase gases into a port on the intake manifold. The inlet air is first filtered by the air cleaner and routed to the opposite valve cover from the PCV valve. If there is a loose or leaky hose in the PCV system, the unfiltered air can be ingested through the leak into the crank case. The oil filter has to contain the dirt from all the sources.
Even though this is a relatively new engine, I would inspect all the PCV hoses / piping for leaks. It would not take much of a leak to allow dirt into the crankcase. The PCV valve may need to be replaced also.
Good luck with the detective work.