Phpspreadsheet invalid datatype?

Question

I cant load my .xlxs file to phpspreadsheet the error is:

[07-Feb-2022 11:35:44 Europe/Budapest] PHP Fatal error:  Uncaught PhpOffice\PhpSpreadsheet\Exception: Invalid datatype: d in /home/yyyyy/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Cell/Cell.php:243
Stack trace:
#0 /home/yyyyy/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Reader/Xlsx.php(827): PhpOffice\PhpSpreadsheet\Cell\Cell->setValueExplicit('2022-02-04', 'd')
#1 /home/yyyyy/public_html/admin/1/glskovetes/functions/testing.php(23): PhpOffice\PhpSpreadsheet\Reader\Xlsx->load('testing6.xlsx')
#2 {main}
  thrown in /home/yyyyy/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Cell/Cell.php on line 243