I own a Copper Dreamer mech and loved it so much I recently purchased a Black coated Brass version. Upon receiving it, and after a little troubleshooting, I realised that it is the hybrid top cap of the black version was stopping the mod from firing. The threads on the black top cap are very clean, but still I feel like somehow the black coating is stopping the circuit from being completed. Please see the link to a demonstration.
I have emailed Stan to see if he has any guidance or encountered this issue before.
Have you tried a different atty? If the atty is only just making contact when you use the brass top cap, it could be that the coating, if it's something like cerakote, is just thick enough that there is no longer any contact. A different atty might have a fractionally longer 510.
I was briefly in a vape shop today and a guy there had a hybrid that wasn't firing. I suggested trying a different atty and it fired. We put it down to the second atty having a slightly longer 510.
So after being out all night, came back to it. And yeah I tried a Kennedy which I would say has a pretty decent positive 510 and it didn't work. Then I cranked the atty and top cap as hard as I could and it fired. Threw the Goon back on without even cranking the atty and it still fired. Must have been the top cap, but even now I can loosen the top cap a little and it fires.. must've been tiny bits of gunk in the threads I missed? Either way stoked it's working now.