If you are working far from the ARCHICAD Origin, it can cause various errors in the 3D window, and all over your projects (this is what Erwin mentioned). This is one of the issues it can cause. You can find out more about Far from Origin issues and how to solve them in this Help Center Article.
In the 3D Projection Settings (In 3D right-click>3D Projection Settings), you have a value called (Target) Distance. If this value is too big or too small, the projection plane might intersect with the geometry, and cause this. Please check the target distance, and make sure it is around 5-10 m (like in the base template)
Please let me know if this helped you!
Daniel Alexander Kovacs
Professional Services Consultant
For Troubleshooting and useful Tips & Tricks visit