Excuse the bad description but this is an easy problem to visualize but hard to describe. When printing the first layer on top of infill, the print is effectively overhanging inside the print and will not form the edge of the layer properly. If a perimeter was placed down on the infill which bridges between the infill then that first layer can bridge from the infill to the perimeter.
As an example, this surface layer that is being printed is meant to be flat rectangular plane that is higher on either side and so does not connect to the overall model perimeter. It is this wall mount for the HTC Vive. If there was another internal perimeter around the surface where the red lines are marked, the surface fill would be much more successful as the surface layer could bridge to it.
In other words the red line marked in this layer preview should be printed in before the fill of the first top layer to allow for it be used as the end point for bridging from the infil for the edge of the surface