It seems Cura 2.3.0 doesn't want to show the 100% infill and it wont print it either way.
And Cura 2.1.3 does well with showing the infill and printing it.
Cura 2.3.0
Cura 2.1.3
Also the Dimensions of the model seems off.
Dimensions in Cura 2.3.0: 33.5mm x 33.5mm x 9.0mm
Dimensions in Cura 2.1.3: 33.4mm x 33.4mm x 9.0mm
So whats up with that?