There are a number of issues that are "possibles".
Inadequate rattle can agitation. STRONG shaking for a full two minutes... at minimum.
Re-coating too soon - which does not let the undercoats "gas off", and in fact will "resolvent" the undercoats.
Coating thickness is too thick. You can build thickness, but it must allow adequate time for undercoats to gas off the solvents.
Applying too thick, too soon will cause the finish to be soft for quite a while. Quite a while could well be months, or longer. Eventually you'll have a very tough finish if you went thick too fast. Deft is very forgiving, but the additives that make it forgiving (flow out agents, anti fisheye agents, antiblush agents) also make it softer than a commercial grade lacquer would be, based on the same rate of application, resulting in similar finish thicknesses. That is, coat for coat, commercial lacquer goes on thicker and harder, but is less forgiving. Deft is good, you just gotta go slow!