PhpOffice\PhpSpreadsheet\Helper\Html() used for set html to cell, but russian charactor change to some special charactor

[alagesanbe08]

This is:

PhpOffice\PhpSpreadsheet\Helper\Html() used for set html to cell, but russian charactor change to some special character

What is the expected behavior?

Смеситель для раковины Jacob Delafon Aleo E72277-CP

What is the current behavior?

Сме�и�ел� дл� �аковин� Jacob Delafon Aleo E72277-CP

What are the steps to reproduce?

 require __DIR__ . '/vendor/autoload.php';

// Create new Spreadsheet object
$spreadsheet = new \PhpOffice\PhpSpreadsheet\Spreadsheet();

$wizard = new \PhpOffice\PhpSpreadsheet\Helper\Html();
 $value = "Смеситель для раковины Jacob Delafon Aleo E72277-CP";
$cellValue = $wizard->toRichTextObject($value);
         print_r($cellValue);                   

[MarkBaker]

You need to pass UTF-8 to the helper, same as setting cell values from strings should always be UTF-8. Is this a UTF-8 value?