Dropdown property in AppMaker not working -

i trying dynamically change nullitemname property of dropdown in google appmaker. however, seems ignoring it. here code , log results:

console.log('debug before nullitemname ' + widget.nullitemname);             widget.nullitemname = 'test'; console.log('debug after nullitemname ' + widget.nullitemname);  debug before nullitemname no selection debug before nullitemname test 

so appears work, widget still shows "no selection".

is there else have do? or bug?

thanks tips or pointers.

seems bug. i've created issue track it. report.