When using SCADE OpenGL rendering code in Qt 5.x, it's flashing, but in OpenGL 4.8.5, it's not

I try to use both QWindow and QGLWidget to calling SCADE OpenGL rendering code under Qt 5.x, both works but flashing, and the flashing is a bit random.
When using the same copy of code by using QGLWidget to calling SCADE OpenGL rendering code, it's works and not flashing.