404 in gutenberg autosave of a Custom Post Type with custom rest_namespace

I'm having some troubles with CPTs defined with custom rest_namespace at register_post_type. I keep getting an 404 error at the console. The error shows that the namespace is not being changed in autosave route.

WP default namespace: wp/v2

Custom namespace defined: ek/v1

I dug into the core classes to find how Wordpress handle custom namespace.

The WP_REST_Autosaves_Controler define the namespace using get_post_type_object at the __construct method:

...
$post_type_object = get_post_type_object( $parent_post_type );
....
$this-namespace = ! empty( $post_type_object-rest_namespace ) ? $post_type_object-rest_namespace : 'wp/v2';
...

If I do a discovery request at the ek/v1 I can see the endpoints registered correctly:

/ek/v1/releases/(?Pparent[\\d]+)/autosaves/(?Pid[\\d]+)

But in the console this error pops up:

GET http://localhost:8888/wp-json/wp/v2/releases/70/autosaves?context=edit_locale=user 404 (Not Found)

So, why the default namespace persist if I did all right? Would it be some javascript function of wordpress that would be doing the request on the incorrect route? What function? How to fix it?