Did you create a filament profile for your filament? Maybe like described here?
You need to define it and set it to the filament you use.
On top of that I would use Concentric or Archimedean Chords top layer for round or not rectangle top layers and I maybe would set Smal area flow compensation to achieve nicer tops.
I use this as my standards in Orca and CP6 prints on K2+.