I added a watermark (i.e., DRAFT) to a template that I am using for a
master document. I have removed the watermark, from the template, the
master document, and the individual subdocuments.

However, the last subdocument keeps showing up with the watermark. When I
open that document separately, it doesn't have the watermark. It only shows
in the master document. At one point, I checked the document before it and
found that the watermark was there when it was opened separately. I figured
that was the problem and thought it would be solved when I removed the
watermark from that (the second-to-last) document, but I was wrong. The
watermark is still there in the last document.

How can I get rid of it?