Interior wall gap?

[secpro 0]

This photo shows the first couple layers of a print. So this is the bottom of the print. What might cause the gap between the interior wall of the round hole and the best of the bottom?

 

The extrusion seems to be enough that the rest of the bottom is filled to make a flat surface, it's not severely under extruded. The outer wall doesn't have the same gap, though there is a noticeable change between the out wall and the rest of the bottom.

 

This problem continues on higher layers, but becomes less severe, as each layer partially fills the gap.

 

Why the gap around the holes the interior wall?  Are there any settings I should look at changing?

Edited May 21 by secpro
Clarifying

[Slashee_the_Cow 382]

If you could provide the Cura project file (.3mf, get it set up in Cura then go to File > Save Project) then we can have a look at all of your settings and such but just going by a photo it can be hard to tell.