you can try re torquing the head and verified non of the hardware got loose. you can check coolant to see if you getting oil in there and add some oil dye to verify it’s coming from there before you pull head off. gasket could have gone bad, boost can lift the head off the cylinder during high boost, multiple reason could be the issue. you could try taking the head torque to the top of the torque spec range to see if that helps. are you using a head stud kit?