Been a while but the dry Irish stout kit from NB was one of my best dark beers. Are using RO water when doing the kits? That will likely solve your problem, along with fermentation temp control and appropriate pitch rates.
Kegged: Waldo Lake Amber, Notty as Helles, Vanilla Porter, Sweet Stout (nitro), NB Surly Furious Clone, Petite Saison D'ete, Le Seigle Belge Saison, BM Cream of 3 Crops, Edworts Apfelwein
In Process: Braggot
Upcoming Brews: Surley Furious Clone, Uintah Wyld