I have found that Mod Podge can be a little bit tacky at first after it dries. I think it has to "cure" for several days before the surface becomes fully hard and non-tacky.
the gloss lustr'e bottle says to use clear acrylic sealer over modge pode to eliminate tackyness, don't know what that is or where to find it.. I used it on a sara binder book and it took a few days but the tackyness did go away,( no sealer)don't know if that will help