I suggest two ways.
Are you using an “author, year” style or numbered? If Author, year, try switching to a numbered, in order of appearance (Science or Nature) (which will also delimit the region that the citation is hidden).
Endnote has two ways that a reference could be “hidden” (@@hidden is appended to the temporary citation (and then the switch to numbered won’t help) or the author and year are “omitted” from the temporary citation {, #2442} (in which case switching to number will reveal the citation again).
{Wang, 1984 #4029;Crews, 1982, 83067444;Howell, 1997, 9009273;Zimmermann, 1997 #4337;figure, 2004 #5253;Goliger, 1992 #1350;Price, 1991 #2966;Pearce, 1992 #2973} another one {, #2442} or {Author, Year #2442@@hidden} and if so, then the temporary citation would show this way ( after you “convert citations and bibliography” and select “convert to unformatted citation” option).
I am not sure where “Edit Sources” dialogue is – in windows, the ribbon option is to edit and manage citations - see attached image with the option circled. The extra record should show up in that list too - in my image, I edited the citation to be hidden) and you can delete it from the drop down at the end of it.
