Has anyone ever had a problem with a Fumoto valve leaking?

Driving from Kingman AZ to northern Nevada as I was leaving Las Vegas we went to switch drivers and noticed engine oil on left running board and fender. Looked under the truck and there was oil on the trans filter, trans pan, and all over middle and left underside of truck.

Limped to a station and bought oil and paper towels. Took 2 quarts. Wiped down the underside and crammed a little piece of paper towel in the drain on Fumoto valve. Every 50 miles or so stopped to check for leaks and nothing since all the way to Battle Mountain.

2006 K3500 D/A