Hm in that case I'd very thoroughly check the oil pan gasket or oil pan itself for leaks.
With a leaking oil pressure sender or front crank seal (I've had both), the oil usually runs along the ledge on top of the oil pan, then drips down near the front differential.
I'll have to look closer, where does it hit the diff? Above the "driveshaft line"?
Except for the fact both will get oil on those spots too...when you drive...it moves backward.
Yeah...the highest and most frontward wetness is the oil pressure sensor, so I guess start there.
FWIW, the engine skid is dry. It's the trans one that gets wet.