Issue with getting full library

[mdomas1]

Hello, I am having trouble getting the full DGX library to work. For example the following works with no problem:
dgx:DataGridFilter.GlobalFilter="{Binding GlobalFilter}"

But, when I try to use the next one, I get an error saying "The attachable property 'IsAutoFilterEnabled' was not found in type 'DataGridFilter.'
dgx:DataGridFilter.IsAutoFilterEnabled="True"
And similar errors for the following:
dgx:DataGridFilterColumn.Template="{StaticResource MultipleChoiceFilter}"
dgx:DataGridFilterColumn.IsFilterVisible="true"

Maybe I imported the nuget package incorrectly, am missing a dependency, or something completely else.
I am using it on a WPF application in VS2019, so I went to Manage Nuget Packages, found DataGridExtensions, installed it, and then even installed it through the Package Manager Console as such:
Install-Package DataGridExtensions -Version 2.5.1
Am I missing another step?

[mdomas1]

I realize now this is a duplicate of another issue here #53 and is a XAML viewer issue.