BUG: setValue in formulas automatically sets @ in formula when using ranges

[HAL0594]

This is:

- [X ] a bug report
- [ ] a feature request
- [ ] **not** a usage question (ask them on https://stackoverflow.com/questions/tagged/phpspreadsheet or https://gitter.im/PHPOffice/PhpSpreadsheet)

What is the expected behavior?

when defining my form I am doing it in the following way

$formula = '=IF(A' . $row . '<>"",SUM(SUMIFS(\'TABLE1\'!C2:C713,\'TABLE1\'!A2:A713,\'WORKSHEET\'!$H$' . $row . ':$Q$' . $row . ')),"")';
$cell->setValueExplicit($formula, \PhpOffice\PhpSpreadsheet\Cell\DataType::TYPE_FORMULA);

but when generating the .xlsx document an @ has been automatically added to the range preventing it from being calculated correctly, for example:

=IF(A19<>"",SUM(SUMIFS('TABLE1'!C2:C713,'TABLE1'!A2:A713,@'WORKSHEET'!$H$19:$Q$19)),"")

What is the current behavior?

    for ($row = $range[2]; $row <= $range[3]; $row++) {
        for ($col = $this->getColumnIndex($range[0]); $col <= $this->getColumnIndex($range[1]); $col++) {
            $cell = $sheet->getCellByColumnAndRow($col, $row);
            $formula = '=IF(A' . $row . '<>"",SUM(SUMIFS(\'TABLE1\'!C2:C713,\'TABLE1\'!A2:A713,\'WORKSHEET\'!$H$' . $row . ':$Q$' . $row . ')),"")';
            $cell->setValueExplicit($formula, \PhpOffice\PhpSpreadsheet\Cell\DataType::TYPE_FORMULA);
        }
    }

Which versions of PhpSpreadsheet and PHP are affected?

v.1.28

[oleibman]

See #3659 (comment) for an explanation of the at sign. As I mentioned in that comment, I haven't been able to figure out what has to be done to keep Excel from adding it (it is not present in the spreadsheet generated by PhpSpreadsheet).