The only time that I have had such a thing happen with lacquer was on a resin cab that didn’t have the resin mixed properly and I guess the paint reactivated the resin. It would literally never dry. Is this only on one particular project or on multiple models? Could it be such a reaction in your case? Is it on resin or styrene? If only it is on only one project, maybe try the same paint on something else and see if it reacts the same. Just a thought.