Possibly condensation but I would lean towards environmental if you are sure the orings are good. We have a 5000' high pass between us and a nearby town we often travel to. We are just over 3000' here and the town is around 2500'. Going over that pass will tend to make a tank flood especially if it is low (air expands) and/or if it is not in continued use (chain vaping). The use seems to keep the liquid used as the air forces it out and a full tank just doesnt build pressure the same.
I mention this because there are loads of different situations where this comes into play like with the temperature change I mentioned before. One constant with environmental is that it is more likely to happen with a not full tank since it is the air not the liquid changing the amount of space it wants to take up.
At the end of the discussion it could well be the cartomizer, I am always hesitant to blame the cartomizer though because I have seen so few fail with no possible reason other than a bad one. The one I have in my tank right now I kind of got a rough start on. I generally tend to prime a little dry so it is critical to make sure it is going well before applying much power to the coil. Well this one was a quick swap because I sat on my provari as it was in my garden tractor seat and broke the cartomizer that was in the tank, tank was 90* to the provari but other than the cartomizer everything was fine.
I did not take the normal care in low power to get it going then after it was going it seemed like it was tending dry. I put a few drops in the top of the cartomizer and it seemed fine for awhile then went towards dry again. Well I finally took a few seconds and looked at the power setting and from jostling in my pocket while working outside it had moved up to 4.5V which would have been fine had a primed my cartomizer to a slushy top but being dry it was too much power and trying to give me that bit of a burned taste. I turned it down to 4.0V and it has been working beautifully since.
Vaping is a dance, when you find that rhythm it is graceful and satisfying. Without it there is nothing but sore toes
