Missing Objects in NSWindow

I create an NSWindow in Swift and add a number of NSVIEW based objects to it.

BUT only the last object added is visibile…. the NSWINDOW structure shows all objects are added, and none are hidden and none occupy the same space

flipView: (0.0, 0.0, 1600.0, 1198.0)
  IDE_STATUSBAR: (0.0, 1158.0, 1600.0, 40.0)
  IDE_NAVIGATOR: (0.0, 0.0, 300.0, 1158.0)
  dsSPLITTER_V: (300.0, 0.0, 10.0, 1158.0)
  dsSPLITTER_V: (1348.0, 0.0, 10.0, 1158.0)
  IDE_INSPECTOR: (1358.0, 650.0, 242.0, 507.0)
  IDE_DESIGNER: (310.0, 0.0, 1038.0, 1158.0)
  IDE_TOOLBOX: (1358.0, 0.0, 242.0, 640.0)
  dsSPLITTER_H: (1357.5, 640.0, 242.5, 10.0)

in this case only dsSPLITTER_H shows, if I comment it out, then IDE_TOOLBOX shows etc.

Have not solved it yet, but did discover I was using a version of my custom framework that was like 3 years old, so am updating the code to use it, but there are a lot of name changes to contend with

well I replaced tmy GUI framework with the latest version and the issue remains only that last added view is visible

well almost… seems the last FOUR now show

statusBar!.addToView(self) // self.contentView?.addSubview(statusBar!)
navigator!.addToView(self) // self.contentView?.addSubview(navigator!)
inspector!.addToView(self) // self.contentView?.addSubview(inspector!)
designer!.addToView(self)  // self.contentView?.addSubview(designer!)

// the following are visible, but if I comment them out, some of above are then visible
toolbox!.addToView(self)   // self.contentView?.addSubview(toolbox!)
vSplitter[0].addToView(self)  // self.contentView?.addSubview(hSplitter)
vSplitter[1].addToView(self)  // self.contentView?.addSubview(hSplitter)
hSplitter.addToView(self)  // self.contentView?.addSubview(hSplitter)

```

when shown in the Xcode Debugger, it shows all the view exactly as expected, but the compiled app does not

this is what Xcode shows in the Debugger View,

But this is what shows when its running, and again, if I comment out some of the addtoview, I can get other parts to show,

seems something changed in recent macOS or Swift…. that now requires more use of CLIPTOBOUNDS, or at least adding a few of those solved the problem it seems