Still having problems with the go-
tanks.

I don't know what I'm doing to them but they always end up leaking after 2-3 fills. It really sucks because I absolutely love them, and am really beginning to hate carts.
At some point the rubber inside stops sealing at the mouthpiece. I had previously raised the rubber to get the contact back, and it's still leaking. I noticed that the clear 'tube' has been coming loose from the bottom, so I started pressing it back down. That usually solves it for 1 fill, then I once again have a leaking tank.
I've tried completely disassembling it, cleaning it well, putting it back together, that works for one fill if I'm lucky then it's leaking. The center tube is crooked in a couple, can't seem to resolve that. I'm sitting here staring at 5 tanks that I refuse to throw away, but don't know how to fix either.
I was thinking if there was a rubber washer at the bottom of the clear tube it would help, but that would cause the rubber piece on the center tube to not be able to seal with the mouth piece.
Really hate using these cartos. I seem to be the only one having all these problems with them cause everyone else is saying they can use them for months. What am I doing wrong?
I have never direct dripped, but was reading about it. Can you direct drip with these cartos?