Need help on spraying clear coat

I have a Kryton clear coat with gloss for acrylic paint. I apply on an unpainted plastic as I wanted it white and my wait time is around 20 min to 45 min for each coat. After applying 2 to 3 coats I've noticed that part of the plastic is glossy and part of it is not so I sprayed it again hoping that this would cover the entire plastic. When it dried I noticed that part of the gloss that probably got over sprayed turned to flat as in the gloss completely disappeared. I've tested it on another plastic and it did the same as if it was sanded. What I don't get is why the clear coat would removed the gloss? Is there a proper way to do this ?