Some information that might be useful when you want to 'fix' non uniform looking plastic mouldings as in your case.
I use a silicon based liquid called ARMOUR ALL
Get a small dab of it (spray it onto a cotton bud) and touch up the discoloured part of the plastic - just on the edge moving it into the 'good' part of the plastic. See if it improves the damaged area and if it blends into the remaining plastic moulding.
What you are doing with ARMOUR ALL is applying a thin layer of silicon (can be thicker by applying more) over the plastic and this will act as a 'micro filler' in effect diffusing the visible imperfection and blending it with the rest of the plastic.
If it works - enough to hide the imperfections - then apply more to cover the complete area as well as the rest of the moulding around the section in question. Once fully dry - you can 'buff' it with microfiber cloth.
You never know - this might 'fix' the imperfection.
But to your original question - I would try to exchange for new device - it should have not passed QA - especially if it’s on front of scope in predominate area.
Good Luck