A family of Microsoft spreadsheet software with tools for analyzing, charting, and communicating data.
Figured out a workaround: When converting an Excel workbook from an older version to a newer one, it has this glitch. But if I start a new Excel workbook and copy over all of the data and formatting to it, it eliminates this problem.
Not sure what's causing the problem, but at least there's a workaround: start a new workbook, copy data from old, paste to new.