I have a terrible blemish on the side of my 2018 R200. It starts halfway back on my black section and goes from a nice shiny gelcoat to a scalloped, textured black that you can't see a reflection in. Like you, I could not see it until it was in the sun and we bought it in Feb so didn't see it until after it was home. I immediately got it into the dealer. They wet sanded it and was shinier for a little bit but is no better now. Took it back to dealer a second time with no satisfaction. I gave up after that and just let it be an advertisement for Robalo quality. And yes, I was and am pretty sick over it. We basically like the boat but this one never should have left the factory.
Good luck and if it is any consolation, the fish don't seem to care.