Models keep moving

[Box]

This might be the solution you need.

SketchUp takes over every Space (Desktop) on Mac OS [resolved]

Click and hold on the SketchUp icon in the Dock. Select Options on the menu. In the bottom part of the menu, “Assign To”, you will see that “All Desktops” is checked. This Options menu uses “Desktop” to mean what you called “space”. Choose either “None” to let SketchUp appear on whatever Desktop is active when you open it, or “This Desktop” to pin it to the current one.