Nothing to do with Zotero, but double-clicking on the footnote anchor (the little number at the beginning of the note) will do that.

It does work in native endnotes created directly in Word for Mac, but not in the Zotero endnotes. If I double click on the endnote number the entire text becomes highlighted (see below) and nothing at all happens in terms of cursor movement back to the referred to text. I have created the endnotes as I always do in the New England Journal format, and then said "Add/Edit Bibliography" and put the Bibliography on the last page. Will it work if I do it another way??

Thanks so much,

Jim

https://s3.amazonaws.com/zotero.org/images/forums/u1002281/aouqfgb9yrpr4rmkzorl.png

If you use a style that actually uses footnotes -- like Chicago Manual -- that uses native Word notes, which will work as described. Since you said "footnotes" that's what I assume you used.
Numeric citation styles like NEJM (or Vancouver or AMA) work completely differently under the hood and linking has been requested a bunch (both for these and author/year styles) but is a fairly complex problem to solve given how citations are generated by Zotero and likely won't happen any time soon. There are some custom macros on the forums that can kind of get you there, but it'll be a bit fragile.

No -- virtually no medical styles (except medical ethics or medical history) use note styles. They're almost all more or less Vancouver (which, after all, is created by the International Consortium of Medical Journal Editors), i.e. numeric