SAP UI5 Excel Export - duplicating last file

I am trying to download JSON data to an excel. It works fine except when I am running a for loop and trying to download the array in chunks of 25, it always duplicates the last file. More specifically, if there is only one record in the array, still 2 files get created.

Below is my code:

var i, j, temparray, chunk = 25, fileNumber; 

var fileName = "Order export-"; 

for (i = 0, j = oModel.length, fileNumber = 1; i < j; i += chunk, fileNumber++) { 

temparray = oModel.slice(i, i + chunk); 
oSettings = {
workbook: {
columns: aCols
},
dataSource: temparray,
fileName: fileName.concat(fileNumber)
};

var oSpreadsheet = new sap.ui.export.Spreadsheet(oSettings); 

oSpreadsheet.build().then(function () {
sap.m.MessageToast.show("Spreadsheet export has finished");
});