Oil Leak after valve cover and intake manifold replacement

Need your help here folks.
I have a 2014 1.4L Cruze with turbo. I had the diaphragm ruptured on the valve cover. I replaced the valve cover with a dealer version and put on a Dorman intake manifold. After completing the job, the car starts to leak oil by the firewall side; no leaks on the front of the engine. There is no pending or residual code. No issue with the purge valve or any vacuum leak. No oil around the intake manifold. The car runs normal; no roughness.
I am stumped as to what is causing the oil leak. The oil leak is small given the dipstick reading overtime; however, the backside of engine is mess of oil. Don’t like to have vehicle leaking oil or fluid. Did thorough clean down but can’t find where the oil is coming from. Not sure if the new intake is bad and not sure what should be my next step.
Appreciate all the helpful advice and suggestion.