User Coordinate System (UCS) Zooms to Extents Each Time I Open or Unlock It
Issue
You've created a User Coordinate System (UCS), and the viewport keeps zooming to extents (zooming out excessively) whenever you open or unlock it, requiring you to reset your UCS.
Cause
This issue is generally the result of having a system variable called UCSFOLLOW set incorrectly.
Solution
Type UCSFOLLOW in the Command line, and press Enter.
You will be prompted to Enter new value for UCSFOLLOW.
Type 0, and press Enter. Your UCS should no longer zoom to extents automatically.