I’m having the same problem. But James’ solution didn’t work for me. Nothing shows. My code (choosing by value or selectedIndex makes no difference):
const $dd = $w( ‘#21’ );
const opts = [ {label: ‘Brazil’ , value: ‘1’ }, {label: ‘Arg’ , value: ‘2’ } ];
$dd.options = opts;
$dd.selectedIndex = 0 ;