Created attachment 37499 [details]
Screenshot Excel 2016 (Windows 10)

I am facing a problem, when using autoSizeColumn and an arrow character (U+279D) appears in cell content, the column will be sized too small.
This code will produce a file containing the problem:

@Test
void excelColWidthStreamedTest() throws IOException {
	final SXSSFWorkbook wb = new SXSSFWorkbook(null, 5000, false, true);
	SXSSFSheet listSheet = wb.createSheet("List");
	listSheet.trackAllColumnsForAutoSizing();

	Row headerRow = listSheet.createRow(0);
	headerRow.createCell(0).setCellValue("MyLongLongString ➝");
	headerRow.createCell(1).setCellValue("➝ MyLongLongString");
	headerRow.createCell(2).setCellValue("My➝Long➝Long➝String");
	headerRow.createCell(3).setCellValue("MyShortString");

	for (int i = 0; i < 4; i++) {
		listSheet.autoSizeColumn(i);
	}
	File excelFile = new File("testFileStreamed.xlsx");
	try (OutputStream fileOut = new FileOutputStream(excelFile)) {
		wb.write(fileOut);
	}
}