Oil pan rear mating surface

Changing the leaking oil pan gasket in my 89 XJ 4.0. P.O. used a cork multi piece and the RTV started working itself out of the front. I replaced it with a Felpo but it leaked and dripped from inside the flywheel cover plate. I dropped the pan again, and thought maybe the P.O. was on to something due to the “seen better days” condition of the pan. I replace the Felpo with a multi piece cork gasket. It leaked again, same area.
I don’t think it’s the RMS because the P.O. just replaced it recently.
Any-hoo, I was looking at the area where the pan bolts up to the block. Specifically the end cap area. There’s a black gasket/seal on the crankshaft that lines up with the curve on the back of the oil pan gasket. It looks exactly like the rubber rear seal that came with the multi piece cork gasket. I tried matching them, without removing the piece on the crank. The pan gasket part seems to be smaller but I could be wrong.
Does the rear curve of the pan gasket mate to this piece of rubber? Or did I fail (miserably) to remove the black rubber gasket from the P.O. multi piece gasket? It’s seated pretty good and I didn’t want to just pull it off in case it was supposed to be there. Also, I can’t remember if I removed the black rubber seal from the first pan drop due to growing up in the ‘70s

That black rubber seal over the crank bearing caps is supposed to be removed and replaced. Most gaskets should have this. Most have a little tab that fits into a notch on the cork so they will seal around each other.

Yep, Thanks for the reply. First time inside an oil pan. The way it was stuck in the bearing cap groove I just figured it was part of the engine. That’s why that gasket never sealed. On the plus side, I’m getting really good at dropping the oil pan. Thanks again