Clone means it's made by someone other than the patented company. Lots of chinese companies will make knockoffs, those are called clones.
Anyways, your battery is the eGo-T, what is the tank you use on it? My best guess is that you're using the wrong coils for your tank/battery. Resistance, voltage, amps, they all go hand in hand. Your battery will detect if you're trying to do something it can't handle (I believe, I actually can't find much information on that specific one, but I imagine it's regulated). So, as you work in a coilhead the cotton will start to clump together a bit, and it will often result in a changing resistance. When I wick a coil and toss it in I'll see the registered resistance go from say a 1.5 to a .9 to a .6 then to the .2 it actually is after a few rips.
I imagine that could be a contributing factor here. That perhaps even though the coil initially works it's actually the wrong coil for your setup, and once it's worked in the system rejects it as it's fallen outside the acceptable range.
Other than that, check the connections, heat can cause things to loosen up, tighten things down (snug but not too tight), maybe clean the connections.
When I first started I used to be sold the wrong coils ALL the time, I didn't go to a vape shop, just a smoke shop. They had the stuff but I had to really be on top of getting the right thing as even if I asked for something by name they'd hand me the wrong thing. Point is, don't just trust the sales people, double check things yourself. Look to find what your tank is, find out what coils it's supposed to use, and find out the resistance it's supposed to be set to.