Studio3D does not render when driving Qt Quick via QQuickRenderControl

Hello,

I am using a QQuickWindow, QQuickRenderControl and a QOffscreenSurface to render a Qml scene into an OpenGL framebuffer object.For this reason , I am using qt example Qt/Examples/Qt-5.15.2/quick/rendercontrol as a base with some minor modifications.

What I am trying to do is that using Studio3d inside qml but can not show Studio3d user interface on offscreen surface, only other qml components are rendered correctly.

If I use QQuickView instead of offscreen surface then Studio3d is rendered correctly.

For test purposes, I used Qt/Examples/Qt-5.15.1/studio3d/simpleqml/ as a base for Studio3d and combined renderControl example for offscreen surface usage.

I am attaching test application to reproduce the issue.

Could you please check the issue and help me on this ?

Regards