I would love to help, unfortunately I'm having difficulties comprehending the problem despite reading your post 5 times.
Ce5 :
Top coil clearo
Wicks kept juiced up through capillary action
Potential for leaks = close to nil if silicon grommet on top fits properly. But if cotton is used as wicks, the likelihood increases slightly. If topper is laid on its side, depending on the amount of juice in the tank, chances of leakage may increase or decrease.
In short, the most likely place for gurgling in a top coil would be the top silicon grommet is not sealing up properly. When you take a vape, your ce5 should not have any vapor in the tank (a bit is fine). If there is, it means there is a breach.
Another possibility is that condensation from the vapor flowing down the Centre tube.
That's what i can think of at the moment.
Edit: just realised this is from a location specific forum. You might get better replies if you post in the clearo section.