Top Layer Calibration Question

Hi All - Slightly new to the 3d Printing world so forgive me. But I’m trying to tune my printer specifically for Bambu PETG-CF. I ran the two new calibrations in Bambu Slicer but still not happy with the results.

Why does my top layer not appear to be fully filled in? Is this a flow ratio issue?

From my amateur eyes, I it appears only the edges of the top layer infill are under-extruded? The top layer infill itself appears smooth and fine, just where it stops and meets the outer walls.