When you have the record open, do you see the “show empty fields” in the upper right hand corner? (make sure the full view is open, so you are missing parts of the window off screen.) Is that what you need? or do you believe you have lost information that used to be contained in fields? Usually a field, even if it doesn’t exist in a ref type, that contains information, will be displayed.
EndNote Tech support sent me the embarassingly easy solution: click on the small “Show Empty Fields” button I hadn’t noticed on the upper right of the edit window opened by the Quick Edit button or by double-clicking on the reference.
The fields weren’t missing, just hidden – I’m guessing because they were created or imported differently than my others.