Should the paint on a 2004 Buick that was repainted in 2006 have the paint peeling off the bumper?

I have a 2004 Buick Century that was in a crash in 2006 and so the front of the car had to be repainted I now noticed the other day that the paint is starting to crack on the pumper and is starting to peel back, should this be happening to a car that had the bumper replaced and repainted 4 year ago? It only has 49,000 miles on it and isn't driven a lot.Should the paint on a 2004 Buick that was repainted in 2006 have the paint peeling off the bumper?No should last longer than that ,what probably happened,is when it was painted

if the bumper is plastic or fiber glass was not correctly primed or undercoated withthe correct

plastic primer ,so they probably just used ordinary metal undercoat,so it cracks and moves on plastic.