Nautilus P1 has leaking connections

I found my leak.   It was in the threads of the manifold.    I pulled this manifold out three days ago so I could get an up close examination.   I expected to see a crack or a deformity but it looked perfect so I re installed it.   Changed the swivel connector twice but it still leaked.  Changed the cone washer seal 3 times using different brands. The tighter I tightened  it the more it leaked.    I finally ordered a new manifold and that cured the problem.   I don't know why this leak started because I have winterized properly each of the 9 years I've owned this trailer.     So if anyone has a leak and changing the swivel connector or cone washer does not correct it then order the section of manifold you need. $$