Nut wouldn’t start threw in trash and used old one. I’m assuming burr or wrong thread.

Mine was leaking highly recommend buying if the nut is crossthreaded or not flush with pan. Also when this job needs to be done, I highly recommend getting a gun cleaning kit from Walmart, it's $12. You'll need the brush and has a steel cable you can thread on the brush so you won't have to worry about a string or something like that coming undone or breaking and losing the adapter in the pan.

There was no way to start the thread on new nut. The old one would thread right on.