Proper way of using Inertia Deferred props

[ChrisToxz]

What is the right way to use laravel-data with Inertias V2 Deferred props?

When I do:
songs' => Inertia::defer(fn () => SongData::collect(Songs::all()),

The data is available in the front end, but I'm unable to loop over it.
I'm using React and it says that map is undefined.

When I return the plain results like songs' => Inertia::defer(fn () => Songs::all()),
The Deferred props works like a charm, and I can loop over the results.