I sprayed the same bass with duplicolor mica green, came out great, clear coated with polyurethane,
Ooooh, yeah. That was destined to go wrong.
Acrylic lacquer like Duplicolor (or any lacquer) will continue to gas off under polyurethane, and the solvent gas will soften the poly from the bottom up.

The general rules are: Lacquer over poly, OK - Poly over lacquer, NOT OK.