I think it's probably " Failed Under Constant Testing " - you can work out the acronym ...
CE4s have a life span - this one sounds nackered if it's flooding .. As noted it's probably the rubber seal at the top of the stem , with regular refilling they do fail and you end up with gurgling and a mouth full of
juice ....I've experienced it , it's not pleasant ...
Sorry to keep plugging one product ... But I'd suggest you look at some Kanger EVOD BCCs ... The price initially is not more than CE4 , it's better vape and you can replace the head at the fraction of the cost of a whole CE4 unit, also extremely solid , no rubber flange near the mouthpiece and very short wicks so no taste alteration .. I made the jump .. It's worth it buddy ... Will work on all / most ego threads ...
and as as you mentioned menthol .... Oh boy these thing rock out !!! To a whole nother level