Problem with Visual Stacking of my Patches

I do not know when, but suddenly my patch is rendered as if FaceAlpha is set to a value lower than 1.

Edit: I realised, that the four objects on the second image below are shown in the order they are loaded into the figure. Is there a property that manipulates the visual stacking of Objects?

I want these Objects to be rendered like they are real Objects in 3D, e.g. One Object or face is in front of another, given a certain persepctive, but when you change your viewing angle by 180 degrees, the other Object is in front.

I can see inside the object in the first image below, but not through it. I think I accidently messed with something. Please help!

It looks like this:

This are the Patch-properties:

            AlignVertexCenters: 'off'
              AlphaDataMapping: 'scaled'
               AmbientStrength: 0.3
                    Annotation: [1×1 matlab.graphics.eventdata.Annotation]
              BackFaceLighting: 'reverselit'
                  BeingDeleted: 'off'
                    BusyAction: 'queue'
                 ButtonDownFcn: ''
                         CData: []
                  CDataMapping: 'scaled'
                      Children: [0×0 GraphicsPlaceholder]
                      Clipping: 'on'
                     CreateFcn: ''
                     DeleteFcn: ''
               DiffuseStrength: 0.6
                   DisplayName: ''
                     EdgeAlpha: 1
                     EdgeColor: [0 0 0]
                  EdgeLighting: 'none'
                     FaceAlpha: 1
                     FaceColor: [1 1 1]
                  FaceLighting: 'flat'
                   FaceNormals: []
               FaceNormalsMode: 'auto'
           FaceVertexAlphaData: []
               FaceVertexCData: []
                         Faces: [12×3 double]
              HandleVisibility: 'on'
                       HitTest: 'on'
                 Interruptible: 'on'
                     LineStyle: '-'
                     LineWidth: 0.5
                        Marker: 'none'
               MarkerEdgeColor: 'auto'
               MarkerFaceColor: 'none'
                    MarkerSize: 6
                        Parent: [1×1 Axes]
                 PickableParts: 'visible'
                      Selected: 'off'
            SelectionHighlight: 'on'
      SpecularColorReflectance: 1
              SpecularExponent: 10
              SpecularStrength: 0.9
                           Tag: ''
                          Type: 'patch'
                 UIContextMenu: [0×0 GraphicsPlaceholder]
                      UserData: []
                 VertexNormals: []
             VertexNormalsMode: 'auto'
                      Vertices: [8×3 double]
                       Visible: 'on'
                         XData: [3×12 double]
                         YData: [3×12 double]
                         ZData: [3×12 double]

Also the Depth Illusion is totally gone. On this picture the 4 Objects are not ordered like one would guess by the rendering. The pillar on the left should be in front of the shelve: