There is a bug where KISSlicer place the extruded beads to close in stead of using crowning (only happen in thin walls).
This is giving too much material and look like your problem (took me forever to figure this bug out).
Try to check the slices in preview to control if the beads is getting closer at these places, if they do that is the problem.
To correct the problem reduce extrusion with and/or reduce number of loops, and check bead distance in preview until they are the same in all layers.
/Michael