The first page of the visit doesn't have a "previous page"...
The Previous Page plugin works by storing the value of the current page, and passing in in the next page's page view call, then replacing the stored value with the new "current" page.
Example:
- Page 1
- Currently Set Previous Page value = empty value
- Value stored as a session variable (Page 1) to use on the next page view
- Page 2
- Currently Set Previous Page value = Page 1
- After sending the previous stored value, the new value (overwriting the old value) ("Page 2") to use on the next page view
- Page 3
- Currently Set Previous Page value = Page 2
- After sending the previous stored value, the new value (overwriting the old value) ("Page 3") to use on the next page view
- etc
This is working exactly as expected... there is nothing to fix.