Redact not working correctly

• Extract the first page
• Redact this page
• Put the page back in the document

This can happen if the file was not constructed correctly, or if it has resources (such as images) that are shared across pages. For example, a background image can be used on all pages with a single source stream, so if you redact it on only one page it will apply the same to the others, too. This may not be desired, but that's how it works.

Redact does not work selectively. It redacts all marked items. But it may well be that I don't understand your problem. May be you post an example (obviously with non sensitive information in).