The floor plan view is still mainly a symbolic view of your project, which is mostly good, sometimes has problems. If you want a true plan cut-through of your building, youll have to set the 3D view to top view and make a horizontal 3D cutplane there,and then a 3D cutaway. It's possible to save this view as for example 2D Lines, and even to overlay it on your symbolic floor plan view if you want that. Much work, but possible.
To have SEOs show correctly on the floor plan without workarounds is a high-priority wish.
AC4.1-AC26SWE; MacOS13.5.1; MP5,1+MBP16,1