The problem still may lie in the journal terms list, which may contain the errant entry in the list and be converting to that column. What I am saying, maynot make sense until you read about the journal term list features. If I were you, I would check the entry for that journal, as it is set as a default to collect that information into the journal terms.
First thing I teach people to do, is turn it off, but the only way to clean it up, is to follow the instructions in Tony’s links.
If that isn’t it, or if you change the authors or the year, it also will revert to what was in the original in the travelling library. Make a copy of the document and then try convert to temporary (or unformatted) citations and then update. If a citation has been edited beyond what endnote can find in the library, it will ask you to find the correct record.