Oil leak from Aveo 2009 1.4DOHC ectotec sump sensor

Hi folks. Can you help me I have an oil leak from a sensor (that’s what I think it is) on the front of the oil sump.
It’s not the sump plug and it’s not the oil pressure sensor.
The sensor is black and has electric to it. There is a silver/Alli half moon disc beneath it both parts seem to swivel bit do not tighten.
Oil only leaks after vehicle has been driven.

Not sure how to add photos to this thread.

Checking all images of Chevy sumps and sensors I cannot find one similar looking.

Any help would be appreciated
Richie.