What AttyPops said. If you have something that you can use to measure the distance from the center post to the top of the threads on the battery and compare it to one that works, you will get an idea of the difference. Like AttyPops said, you can bend a tiny right angle on a jumbo paper clip to create a tool that will reach down and grab the side of the center post. The center posts are generally set into teflon or silicone sleeves. Screwing an atty on tightly can push them down. The same is true for atomizers, cartomizers, and tanks.
You can do the same measurement with your tank to see if there's a difference in contact height. This is the most likely reason that one works and the other doesn't. I'd look at center post heights on your atomizer devices first since one works and the other doesn't, using the same battery. The problem is likely center post height in the tank that doesn't work. Just work it up using a repetitive movement with the paper clip. Work your way around the center post pulling lightly until it works with the one that previously didn't.
Here's a link that explains adjustments to the center posts.
atomizer and cartomizer connection problems
