The bottom of my drain plan was definitely not smooth. Had a bump that my nail could catch easily. I sanded it down with some 400 grit.(Before and after pics attatched) I thought that would solve it for sure. I think it's still dripping a little SMH. Even went back to a new OEM plug and put thread sealer permatex. I guess my pan has been cross threaded and plug is not laying flat against the pan. So frustrating. 3 oil changes and still not right.I used an aftermarket magnetic drain plug for a couple years. It would leak unless it was very tight. So I went back to the OEM plug. I would try lightly sanding the oil pan seating area with some 400/600 wet dry sandpaper. There might be a surface defect.