Section viewports (and anything to do with sheet layers) are for putting together a sheet, not editing. You go back to the model to edit and change walls. One quick way to do that is to double-click on the Section Viewport, then choose to return to the design layers, and see that the choice to Display with Clip Cube is selected. This gives you a section view in OpenGL with the same cut plane as the viewport.
Section viewports (and anything to do with sheet layers) are for putting together a sheet, not editing. You go back to the model to edit and change walls. One quick way to do that is to double-click on the Section Viewport, then choose to return to the design layers, and see that the choice to Display with Clip Cube is selected. This gives you a section view in OpenGL with the same cut plane as the viewport.
How do you move objects, change walls,... in a section viewport?