I am using KIS for some time, but not very intelligently

To change that I bought a premium key (and of course to be on front row!)
With the Alpha I went completely blank and made new profiles.
My first calicube looks pretty okay (despite one shifted layer) but has one major flaw, on the upper layer the infill does not touch the perimeters.
This is already visible in the path preview, like this:
The bottom layer infill is just fine. I cannot imagine wich setting would result in this behaviour. Someone?
While we are at it, I have this strange artefact that follows the contour of the X. Ringing? Strange is that it happens in the wrong direction to be ringing. This is certainly no slicer flaw, because I am having these artifact for a long time now. Maybe some specialist here likes to enlighten me about this

Thanks!