Qt Quick 3D Physics example slows down when resizing application window

In the Qt Quick 3D Physics - Material example, the box seems to slow down to half the speed when resizing the application window. This is best noticeable when changing both "Static friction" and "Dynamic friction" to the minimum value, and changing "Restitution" to the maximum value, which will give the box a large bounce. When resizing the application window with these settings you can see that the box is very slow in the air. The moment you stop resizing, the speed resumes back to normal.

Steps to reproduce:

1. Change "Static friction" to the minimum value.
2. Change "Dynamic friction" to the minimum value.
3. Change "Restitution" to the minimum value. This is to see how fast the box slides.
4. Left-click "Reset box".
5. Resize the application window continuously by left-click dragging the bottom-right corner around randomly or in a circle. Notice that the box slows down.
6. Stop resizing the application window. Notice that the original speed of the box resumes.
7. Change "Restitution" to the maximum value. This is to see how fast the box is in the air.
8. Left-click "Reset box".
9. Repeat step 5. Also notice that the box is very slow in the air.
10. Repeat step 6.

Expected behavior:

The speed of the box should not be affected by resizing the application window.