The sill of the Window that does not show is much higher than the sills of the other Windows. Is it above the cut plane in your plan view? If so, and the Above Cut Plane component is turned off (as it is by default in the out-of-the-box display settings), then the Window will not show.
If raising the cut plane height to include that Window causes issues elsewhere, you can override the cut plane for just the Wall that hosts that Window, and raise it to cut through the Window. That can be done with either a style-level (affects all Walls of that Style) or object-level (affects just that Window) Display Representation override, on the Cut Plane tab.
