[TLF 2820847] Bindable values not updated in a TextFlow that contains a link

Steps to reproduce:
1. Compile and run this application:

<s:Application xmlns:fx="http://ns.adobe.com/mxml/2009"
xmlns:s="library://ns.adobe.com/flex/spark">
<fx:Script>
<![CDATA[
[Bindable] public var bindableVariable:String = 'str';
]]
>
</fx:Script>
<s:controlBarContent>
<s:Button label="change bindableVariable" click="bindableVariable = ''" />
</s:controlBarContent>

<s:layout>
<s:VerticalLayout />
</s:layout>

<s:RichEditableText id="ret1" editable="false" selectable="false">
<s:textFlow>
<s:TextFlow>
<s>Bindable variable is:

{bindableVariable}</s>
</s:TextFlow>
</s:textFlow>
</s:RichEditableText>

<s:RichEditableText id="ret2" editable="false" selectable="false">
<s:textFlow>
<s:TextFlow>
<s>Bindable variable is: {bindableVariable}

with link: <s:a href="http://www.example.com/">www.example.com</s:a></s>
</s:TextFlow>
</s:textFlow>
</s:RichEditableText>
</s:Application>

2. Click "change bindableVariable" button a few times
3.

Actual Results:

The first textflow updates fine, but the second textflow doesn't

Expected Results:

Both textflows should update

Workaround (if any):