Spacetop works best in a setting with normal lighting. All AR/VR systems use light in order to track your positioning and movement, and Spacetop is no different.
If you are trying to use Spacetop in a dark room or area, there is a chance you will experience some drifting or other visual issues.
A trick that might fix this is a click on the power button (sleep), and another click after 2 seconds to wake up. You may need to do this more than once Spacetop loses its bearings or if you are moving a lot.
Once you do this, the system will "remap" the room and the drifting will stop. Once you do this pressing "Shift + Shift" will recenter your canvas to make usage more comfortable.