Definitely sounds like there's still water in there. I will clean atties, but that's still a chore getting them completely dry before re-priming them for use. I can't even fathom trying to clean a carto. There's a lot of batting in there with no real way to remove it and press excess moisture from it (like if you were cleaning the filling in a cartridge tip). All you can do is keep blowing and blowing through it, remove the cap and set it cap-side down on a paper towel for a couple of days to drip dry.
Here's how I deal with cartomizers. I dedicate one carto to one flavor (or at least a "family" of similar flavors like menthols or fruit flavors or dessert flavors). I keep it nice and juicy when vaping. I store it with the condom caps on both ends to keep everything from leaking out. When they stop producing tasty, dense vapor I toss them. Seriously, they're meant to be disposable, even if they can be refilled several times before the atty starts to go kaput. While I'd never vape one dry and then toss it, I won't clean them the way I will atties.
