Re-wicking may be the way you have to go on this one, or fluffing the existing wick out.
I have been using mine for 3 days with the 2.8ohm head on Vtube at 4.5 to 4.7V. I found that if the juice gets low in the tank I occasionally get a dry hit but if I turn it upside down even for a second it's fine. I also vape with my PV tilted a little bit upwards so that probably helps too.
I am going to play with the 1.8ohm head tomorrow and try the cotton wick idea and re-coil it to around 3.0ohms and see what happens.