Qt 5.9 Flushing OpenGL Buffers

I recently upgraded to Qt 5.9

. The app I'm working on uses QOpenGLWidget

and QOpenGLBuffers

. I noticed that the Qt 5.9

destruction QOpenGLWidget

is very slow and makes the application very slow.

Any suggestions / ideas to help?

[EDIT] It seems to be related to the number of VAO

( QOpenGLVertexArrayObject

) created . Qt 5.9

had to change the way of cleaning VAO

. Using the function destroy()

doesn't change anything.