This is my first time using DCU flex-n-flat clearcoat to get a matte finish.

To my surprise, the upper surface of one wing has come out pretty glossy, wihle the rest of the aircraft is nice & flat. Any ideas what causes such discrepancies ? More importantly, any idea how to fix it ? Whenevr I try to buff my gloss finishes they always end up pretty matte (!), so maybe some light buffing with a cutting compound can dull the surfafce a bit ?