Had same or similar issue about 100k miles ago after an extended OCI.
There are two oil pipes that feed oil to the oil control valve, one on each side of valve cover. At the top of those pipes, there is a bolt that holds it to the OCV. Take that bolt out, it is hollow. On the end of the bolt will be a plastic cased cone shaped filter with a metal screen. It should come out with the bolt, if not use a pick to get it out. Clean it up and reinstall screen, bolt to torque.
Also, pull the cam position sensors on the valve cover and wipe them off, may be some sludge on them.
Check PCV valve or just replace it, its cheap.
Ever since then, I change my oil every 5K.