Bug on Window.resize?

[sonicsoul]

Sometimes, when the window gets manually resized, on some points the sidebar flickers/jumps to the top and stickyness does not work until I resize the page again. The nav-container has no longer the "is-affixed" class and the inner sticky element is only on "position:relative" .
I have the ResizeSensor included and everything else works as expected.

Any ideas somebody?