PanelPage lays out an entire page. It supports several navigation and content areas for the creation of pages. When the panelPage is geometry managed, the last indexed child will be stretched vertically to fit in the leftover space not consumed by the other indexed children. If you do not want this stretching behavior, you must wrap your indexed children with a panelGroup with layout="vertical" and inlineStyle="overflow: auto;". This way, the panelGroup will be stretched to fit and scrollbars will appear when the content inside is larger than the allocated space.