Simple automate script mangles number formatting

Kipopstok The reason it fails is because your recorded code converts string values to numbers. But Office Script expects US syntax for the numbers. So the comma poses issues, as that is normally the thousands separator.

You could try this version of the script (adjust the ranges):

function main(workbook: ExcelScript.Workbook) {
	let selectedSheet = workbook.getActiveWorksheet();
	// Text to columns on range A1:A3 on selectedSheet
	for (let row = 0; row < selectedSheet.getRange("A1:A3").getRowCount() ; row++) {
		let sourceRange = selectedSheet.getRange("A1:A3");
		let destinationRange = selectedSheet.getRange("A1");
		let sourceRangeValues = sourceRange.getRow(row).getValues()[0][0].toString().replace(/,/g,".").split(/[\t|]/)
		destinationRange.setNumberFormat("General");
		destinationRange.getOffsetRange(row, 0).getResizedRange(0, sourceRangeValues.length - 1).setValues([sourceRangeValues]);
	}
}