I had the same leak on mine. There is a bolt with a copper washer under it above the shifter. It looks to be a connecting passage for oil flow. The screw is loctited in place. The torque spec is very low. I loosened the bolt a few threads with a 12mm wrench then tightened it slightly beyond torque spec by feel of hand. Leak has stopped and not come back. I suspect that the torque spec is not seating the sealing washer completely and with 50psi of oil pressure you get a seaping.
Hope this helps!