Style of the grid

Above the grid I have a menu . A menu item has children witch go behind the grid , maybe because of the grid style settings .

How could I make the menu children visible . The issue is reproducible only in firefox

Grid doesn’t have any z-index settings.  So, if  pop-up has z-index  >  0, it should  appear over  the grid.

If you use dhtmlxMenu  and problem persists, please, provide a sample where issue can be recreated ( to ) .