When exporting a dataset to Excel (.xlsx) all the data will show up as text or number cell format. What ends up happening is that if the user tries to edit the Cell in the Excel file, the cell turns black and no text of the edits is visible.
However exporting as an Excel Instance, the file opens and all fields are set to General cell format which allows edits to the Excel file like normal.
WORKAROUND
Use Excel Instances export method and save the file manually.