一些调整大小后，Flowlayout面板不显示滚动条

I have a flowlayout panel and on a resize event, I resize all the controls inside the flowlayout panel so they fit the width of the (flowlayoutpanel - padding - scroll bar width). On some resizes, the scroll bar is not shown, hiding most of the controls outside the area of the flowlayoutpanel while on other resizes the scroll bar is shown.I have set the AutoScroll property on the flowlayoutpanel to true. This is all done using C#, but I have also encountered this problem in VB.net. I have a flowlayout panel and on a resize event