It’s been a little over a month since I got my phone but I don’t recall if there was any plastic covering. If you are near an Apple store take it in to have it evaluated. There could be an issue or there could be a user error issue. Really depends on what you actually have going on. You also have to remember that photos that any of the phone makers advertise tend to look better than the average persons due to numerous factors so it’s hard to say if you actually have a problem that needs to be addressed until it’s evaluated. You may also be experiencing issues that some are reporting on threads on here that may be due to iOS bugs. Has 13.2 update helped any?