Pcv Questions

Today, I noticed more smoke than the occasional tiny puff on take off. In fact, it was a consistent large puff of smoke on take off, I suspected the stupid hot weather increasing oil temps and viscosity, but now I suspect a PVC issue. There is a breather on the drivers side which vents to the air intake tube (after the MAF). The line flows freely, but if I blow into the line, no air flows into or out of the valve cover. It seems to be blocked somewhere internal to the valve cover. Is that normal?

The rest of the PVC system seems normal. The PCV still rattles and all the lines are clear.

Yeah, the tube that goes from the intake to the drivers side valve cover. The tube is clear, but it feels like there is an obstruction inside the valve cover? There isn't a PCV type valve internal or something, like that that can be replaced?

The smoke comes from the drivers side. Ideally, there should be some negative pressure in the valve cover to reduce oil leakage past the valve stem seals at idle. It would be closer to equal pressure so less oil passes by those seals.