Value of FxRadioButton does not change when setting via getRadioButtonAt method

Steps to reproduce:
1. Compile & run:
<?xml version="1.0" encoding="utf-8"?>
<FxApplication
xmlns="http://ns.adobe.com/mxml/2009" xmlns:local="*"
backgroundColor="0xFFFFFF" >
<layout><VerticalLayout/></layout>

<Declarations>
<FxRadioButtonGroup id="srg" />
</Declarations>

<FxRadioButton id="s1" label="Spark 1" groupName="srg"/>
<FxRadioButton id="s2" label="Spark 2" groupName="srg"/>
<FxRadioButton id="s3" label="Spark 3" groupName="srg"/>
<FxRadioButton id="s4" label="Spark 4" groupName="srg"/>
<FxRadioButton id="s5" label="Spark 5" groupName="srg"/>

<FxButton label="Change value getRadioButtonAt" click="srg.getRadioButtonAt(3).value='value'"/>
<FxButton label="Change value" click="s3.value='value2'"/>
<FxButton label="Get value" click="lbl.text=s3.value.toString()"/>

<Label id="lbl" />

<FxButton label="Change label getRadioButtonAt" click="srg.getRadioButtonAt(1).label='New Label'"/>
<FxButton label="Change label" click="s2.label='New Label2'"/>
<FxButton label="Get label" click="lbl2.text=s2.label.toString()"/>

<Label id="lbl2" />

</FxApplication>
2. Click the button "Change value getRadioButtonAt"
3. Click the "Get value" button

Actual Results:
value is null

Expected Results:
value should get set to 'value'

Workaround (if any):