Maybe you are stuffing your wicks too tightly in the coil?
I know I put extra to make sure it does not leak at the wick ends...
I first unsuccessfully cut away some of the center of the wick then finally decided to just create longer wicks that I stuff under at the ends.
Seems counterintuitive and that it would choke out liquid flow, but it does not on these units (2) for me.
I am using 3mm coil with 28ga SS wire 3ml nic at 10.5 to 12 watts dependent on juice and wraps and hit all day and night for about 4 to 6 weeks between new wicks (I have 7 different setups I switch between throughout the day but this and the Vapefly Alberich II hold my 2 favorite flavors that i usually hit on the most each day)...