Language Binding does not update when value of binded property changes

Describe the bug
I have used the following way to bind my label

<Label BorderThickness="0" Content="{ex:Lang Key={Binding AppStatus}}"/>

I have the following keys in my Lang.resx = "Idle", "Searching"
whose values are also defined.
Now the Initial value of AppStatus is set to "Idle"
and it shows and changes as I change language, but when I change the value of AppStatus to something else, say
AppStatus = "Searching"
I expected the value on the UI to change as well(to display the localized value of 'Searching'), but it stays on "Idle".

To Reproduce
Steps to reproduce the behavior:

1. Bind any control with {ex:Lang Key={Binding BindingProperty}}
2. Change the value of 'BindingProperty' to something else from the code
3. The display value of the control doesn't change.

Expected behavior
When the value of BindedProperty is changed, I expected it would display the localized string of new value.

Environment (please complete the following information):

• .net: 5.0
• IDE vs2019
• Version 3.3.7

Additional context
changing value from ViewModel
HandyControls issue

Start by reproducing the XAML binding shown in the issue with a ViewModel property changing from "Idle" to "Searching". Trace the language-binding behavior involved and verify the result against the expected localized value; done means the displayed text updates when the bound property changes.