Not sure, but maybe because of really high resistance coil? 3.2 ohm means you are getting 11,25 watts at the max 6 volts the evic can deliver. But a 3.2 ohm coil is probably very short and/or and thin resistance wire, so you might not have much surface where the juice can vaporize. That might be the reason why even at 11 watts you're not getting much vapor. Power in watts equals squared voltage divided through resistance in ohm (Watts = Volt^2 / Ohm). You should try with a lower ohm coil.
EDIT: I didn't know about this but apparently these are meant for high voltage APVs or something?
"Available in 1.7 or 2.0 ohm low resistance for use with 3.7v, 3.0 ohm for 4-6v and 5.0 ohm for 7+v APV's."
Single Coil XL Tank replacement 510 cartomizer for 3.5 and 6ml SmokTank XL, UDCT, Artemas - w/flange and 1, 2 or 3 holes.
thats the reason i purchased a 3.2 ohm because it was saying online that it can be used at higher voltages and produce more vapor... but my aerotank is 2.0 ohm and i can run it at higher voltages and produce more vapor and throat hit....
im really confused on all this carto stuff.. feeling like i wasted money on a IBtank and the cartos are barely keeping up with my aerotank