Did you try giving it a tiny tweak tighter? I had the same problem twice with an aftermarket plug with a magnet, both times I wiped it down and gave it about 1/16th of a turn tighter, and it resolved the problem. Next OCI I might just go back to the problem free OE plug.
Edit: "I" found the crush washers with that square tab and the one with the black ring to work the best. I have a Dorman transmission pan with a drain plug that leaked like a sieve. The washer with the black ring fixed it perfectly. The crush washer they provided sucked.
I did. I think it's 18 ft/lb and I went a hair tighter but still an issue.
I think OReilly might sell a replacement seal for the OE plug but if they don't, are those blue nylon washer/gaskets a good idea? It has ridges like it's a type of crush washer.