Graphics are calibrated and no similar (or other problems) with any other software, including SolidWorks with it's intensive rendering in FEA and photo rendering with adjustable Light position sources, GIMP, Paintbrush, Coral, Autocad... list goes on . It happens only with s3d whether Legacy Graphics is checked or not (in prefs). Regarding Z-stitching: stitching is app/code dependent (polygon orientation and depth), not machine dependent so, it's s3d code.
A different problem but (on Mac version) right click the Toolbar and uncheck the Toolbar to hide it. Only way to get it back is Quit s3d...
3D Print Parts