QOpenGLContext in a thread crashes if a QOffSreenSurface was created in the main thread

On Windows 64, a QOffscreenSurface is created in the main GUI thread:

surface = new QOffscreenSurface();
surface->create(); 

Then in a thread just:

QOpenGLContext context;
context.create();

crashes Qt on  context.create() instruction, before I even try to use surface. I have tried various things such as setting the context's format or surface's format but none fixed the problem.

If I run all this in the main GUI thread no problem.

If I instanciate and create the surface in the non-GUI thread I have the warning that I should not do that (but it works).

If I instantiate the surface in the main GUI thread but create it in the non-GUI thread, it works, without warning.

I also tested all this under Linux (Qt 5.8), no problems.