Thank you! Alas, in this particular case it's not a very nice solution either, beacuase the staircase is situated in the tower with circular oblique walls. As a result the additional segment of the walls up above gets in the cut plane, and impart the section view an undesired look:
Tricky situation you have there. I was hoping the section didn't need to display the roof. The only alternative I can suggest is you create two views, one a section without the stair and another an elevation (or section) showing only the stair. These can then be combined on a Layout with the stair on top of the section. You may need to do some juggling with trace references for any notation you need to add.
Hope that helps.
Apple iMac macOS Ventura / AC26UKI (most recent builds)