Trouble with upper layers - hardware related?

I’ve been seeing issues with the top solid layers of my prints for about 6 months now. Luckily I’ve been printing parts where the finish of the top layers aren’t important. But now I’d like to get the issue worked out. See below for an example of the issue. It seems like the lines on the top solid layers are too thin. I can actually see through the top layers into the infill. It doesn’t matter how many top layers I add, the issue persists. This occurs in CURA and Simplify3D and I’ve tried different filaments as well. That is why I’m leaning toward a hardware issue. Any advice is appreciated.

Make sure you are using the right nozzle diameter for the profile you’re using. Also, make sure the nozzle is not partially plugged.