Need advice on my 2007 CVO Springer with primary chaincase oil leak.

I have only about 3000 miles on this bike and I have developed what looks like a slow leak from the primary chaincase drain bolt.
I checked it out myself and when I removed the drain bolt, it appeared that someone had used teflon plumber tape in the bolt. Also, the o ring seal was shot. So I removed the teflon, cleaned the parts and installed a new OEM o ring.

So far so good? After a few miles of riding I park the bike in the garage and it seemed fine. However after about a week of sitting in the garage, I see the slow leak again.

Dealer said it could be the gasket at the rear of the chaincase and it just looks like the drain bolt. Hmm. I am guessing the previous owner must have had the same problem as somebody used teflon tape on the drain bolt, I am not sure what the problem is.

I scheduled an appointment at the dealer as I recently bought the bike from them.

Any ideas what is causing the leak? Is there a history of drain plug leaks with the CVO in 2007? It is the only HD out of four that had a leak.

Thanks in advance.

ETA: have done some research here and it is possible that it is the primary bearing seal leak? It makes sense since I did replace the drain plug seal and torqued to 17 ft lb. So I will keep that in mind. About one hour labor and parts in the shop??