Steps to reproduce:

• Create a general empty project with project wizard
• Add QtQuick3D from Components -> +
• Drag and drop two View3D components from Components -> QtQuick3D to 2D View
• Run the project
• Only the View3D that was added last is visible in QML app
• When running the Live preview, both are visible in QML app
• If I import some 3D asset and add that to scene in View3D that is not visible in QML app, then after running the project the imported asset is visible, but other components in scene are still not visible.