If it was working on the old battery, then when you screwed it onto the new battery it didn't work on the new battery, and then also wouldn't work on the first battery, is that correct?
I bought a tank atty/carts last week, got them in the mail on monday, fell in love once I got it working, and ordered 2 new Joye ego-T kits the same day I got it.
I had a problem when I got it though. I screwed in my brand new tank atty after priming it and getting it ready, and it wouldn't work. I pushed the button, and NOTHING. I put a 510 atty on the battery, and it worked just fine.
Turns out that it wasn't making contact with the battery, so no juice (I had a T-Rex setup, it's a Joye ego clone) but not close enough for the tank atty though.
I ended up with the "aluminum mod" LOL, basically I folded a piece of foil till it was the size of a grain of rice, and carefully screwed them together with the foil making the last mile between the battery and atty, if the foil moved from the center and touched the side, the light would blink like it was dead, after slowly screwing it on, while testing it out all the way on I finally got it working. It was very annoying at first, but it did allow me to use my tank and to fall in love with it, as I see you did.
But maybe when you screwed the new battery on it changed something about the connection where it wouldn't work with either battery anymore. Give it a try, and I really hope it works! I now have three tank attys, and would LOVE to get 6 months out of each! Tomorrow is 3 weeks for me off of smokes, and vaping. I chain VAPE, and haven't lost any of my many attys yet, and I'm hoping for a very long life for all of them.
Hope you enjoy your new tank system, this system caused my wife to finally fall in love with vaping, and she is going on 4 days! What a miracle for all of us. Good luck again, and sorry for rambling.