Export data using XLSX vs. CSV files

If you're exporting data from a spreadsheet, follow these rules: 

XLXS – Used to export one sheet in a workbook. The exported sheet must be last in the workbook. For example, if you want to export data in sheet 1 out of 3, Sheet1 should be the last tab.  

CSV – Used to export all the available data. If you're exporting everything, your data should be in one worksheet in a CSV file.