Function to Return Array of Unique Entries in a Range

I have attached a spreadsheet with a UDF to identify unique entries in a range and return an array of only those uniques. However, the function does not work when passed a Named Range, defined by formula (See the Name Manager). It works fine when passed an explicit range reference or an explicitly defined Named Range.

I'm open to better solutions to the problem of returning an array of uniques from a list which may include duplicates. Ideally, any solution needs to be able to handle named ranges defined by formula.

I'm would really like help in fixing my function, improving the speed of my function, or an alternative approach which accomplishes the same thing.

Thank you