Phpspreadsheet ods problem with merge cells

Question

Using phpSpreadsheet 1.16 to generate xls and ods files. Xls files runs correct but ods stuck on merge cells - no error simply forever loading. What can i do to solve this?

$sheet->mergeCells("B".($counter).":D".($counter));
$sheet->mergeCells("E".($counter).":F".($counter));
$sheet->mergeCells("G".($counter).":H".($counter));