I haven't had a problem with it with my two Leafs, and it isn't a commonly reported one here. Either it is something to do with your car in particular (like a blocked condensate drain hose) or it's something to do with how you in particular use the car. BTW, we had a 2010 Prius that we leased for 3 years. Insects or spiders managed to block that hose, the rugs got wet, and we had to replace all of the carpeting because mold was growing in it. The dealership wanted thousands of dollars for that - and claimed that it was a rare issue - so we had exact fit aftermarket carpet installed, for about a Grand.
Scarlet Ember 2018 Leaf SL W/ Pro Pilot
2009 Vectrix VX-1 W/18 Leaf modules, & 3 EZIP E-bicycles.
BAFX OBDII Dongle
PLEASE don't PM me with Leaf questions. Just post in the topic that seems most appropriate.