FireEvent in Flex Combobox

Speak to your devs.

You need to find out what the event trigger is.

It could be field exit (try tabbing out of the active control after making your selection). That's the obvious one.

Or they could have a custom trigger attached to another object (invisible overlay, higher level object, lower level one, relative screen co-ordinates .... who knows!) in the application.

I have a similar thing with a Tree View with checkboxes. You can click a node. But clicking the checkbox triggers custom propagation up and down the tree, dependent on the layer you selected within. But the event trigger looks for a click on the actual tree, not on the node, because that's how they chose to write it. So I need to re-map the node co-ordinates to apply to the tree object and apply the click to that. No WAY I would have worked it out without dev input.

This is not to say this will work for you. It's merely an example.

But only the devs will know how they have implemented their event triggers. We can't tell that.