Switching Tabs Makes CAD Zoom Way Out

Issue

You seem to be experiencing a problem with the origin point. When switching from Paper Space to Model Space, CAD zooms all the way out into space away from the drawing. 

Cause

The issue stems from having the site too far from 0,0. However, the actual zooming extents is the result of an AutoCAD system variable called UCSFOLLOW.

Solution

You can switch the system variable by typing UCSFOLLOW in the Command line. See the Autodesk forum for more information.