getSearchResultsUsing() not working when using relationship

[aryadilas]

Package

Form builder

Package Version

v3.2

How can we help you?

Select::make('direction')
->native(false)
->relationship(
   name: 'region',
   titleAttribute: 'name'
)
->getSearchResultsUsing(function ($query, $search) {
   dd($query);
})

Why is getSearchResultsUsing not working when using relationships? I want to customize the query, but dd() doesn't even show up.