techteacher:
A few things to check:
1.
Filter Elements in 3D... > is this set to Infinite or restricted to a story range?
2. Do you have
3D Cutaway enabled in conjunction with the
3D Cutting Planes...?
If not, a screen shot might help diagnose the problem.
You should add a Signature to your Profile (click the Profile button near the top of this page) with your ArchiCAD version and operating system (see mine for an example) for more accurate help in this forum.
David