It works fine on my machine.

I'm thinking that perhaps you are 'editing' the source text by typing on the end (after the 1 in Document 1). This is not how you need to edit the text when it is bookmarked - Cross-refs work by adding a hidden bookmark around the text and then creating a Ref field which points at that bookmark. If you edit text so the new text is still inside the hidden bookmark then the Ref field will update to show those edits BUT if you add content at the location where the bookmark ENDS then the added text is outside of the bookmark. Conversely, if you add text in the location where the bookmark starts then that added content IS INSIDE the bookmarked range.

So edit the text by adding your content one character earlier, and then delete the last character. Then try updating the cross-ref.

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Andrew Lockton
Chrysalis Design, Melbourne Australia