For example : General/Document, Display/3D view, Start, Sketcher/General, ...
I guess the culprit is Sketcher/General as this looks like the most overloaded page. Other pages like General/Editor have either set the size policy to expand or use spacers to occupy the available space. But these pages do not prevent the user from making them smaller.
But worse, as you can see below on a screenshot (full screen height), there is no scroll bar in the left pane so I'm not able to reach the settings below Sketcher (eg. Draft, Techdraw)...
That's odd. When I load all workbenches then the list view shows a scroll bar to me. But nevertheless you should still be able to navigate to all groups by either the mouse wheel or by selecting an item and then use the arrow down/up keys.
Fortunately on Linux, the window can be maximized, which makes the scroll bar to appear in every pane (widget layout recomputing I guess).
Then maybe something is wrong with the logic to show the scroll bar.
I opened Preferences and now all tabs have vertical scrollbars even the ones that dont need one.
This is because the widget container that keeps all pages itself will be embedded into a scroll area widget.