DropDownList -- if one sets selectedIndex=1 , it gets automatically set to -1 if user does not open/close the dropdown after changing the selectedIndex to some other value

Steps to reproduce:
1. Run the attached file .
2. Press the button "LETTERS" once. All the components get set to index =1 through the code.
3. Press the button "LETTERS" again. Code is doing nothing but setting the selectedIndex=1 for all components.
All the components get set to index =1 through the code but for DropDownList gets set to -1 automatically.

Actual Results:
DropDownList sets to -1 index and other components are set to 1 correctly.

Expected Results:
DropDownList should be set to 1 index as mentioned in the code .

Workaround (if any):

If we call the selectedIndex call later by using callLater and then validating the displayList.

Attached are both the files .

DropDown.mxml ----- Error Reproduction File.
DropDown_workaround.mxml — with workaround.