Exception.Source generally works only when we use a try catch around invoke workflow file…that is say if an activity in a xaml is failed and that xaml is called from another xaml and this outer calling xaml is having try catch then it will give the activity name else it will not give the activity name but it gives the type
As you are on studioX you wont have multiple xaml files I believe…I doubt we can get the activity name directly by using it
You need to follow the approach 2 mentioned here where manually you need to update the name of activity before every activity
Cheers