The chaincase oil can wick up thru the wires from the stator and run out the plug. This oil will end up causing the pins to burn thru in the plug. I've had luck coating the inside with silicone. The stator plug pushes in to the case from the inside and is supposed to be a snug fit with enough sticking out to go fully into the VR female end of the plug. On the end of the stator plug is a flange which is supposed to seal the oil. I put them in with a bit of silicone to seal them, your's either hasn't done that or the silicone is so old it is not sealing. If the plug is not through the case enough you might be able to pull it a little further gently, but don't go crazy there. As mentioned a bit of silicon squeezed around the edges might fix it as it is primary fluid and not under pressure. Clean the surfaces well with some wax and grease remover before applying the silicone