[OSC911]

Do you have the turbo cam restrictions fitted? Probably isn’t going to help with the diagnosis of your original problem but might assist with oil pressure increase.
https://www.pelicanparts.com/cgi-bin/smart/more_info.cgi?pn=901-105-361-02-OEM&catalog_description=Restrictor%20Fitting%20for%20C amshaft%20Oil%20Line%20at%20Camshaft%20Housing,%20 Brand:%20Genuine%20Porsche%20Brand:%20Genuine%20Po rsche