wp_update_user() and then stops

Hi, I’m working on my own function to update some user profile data using ajax.

On the server-side, I’m using the WordPress function wp_update_user().

When I update for example the display_name (in the wp_users table) everything goes smooth, I send My ajax (post) request, and I get the data I’m expecting in return and the display_name is updated.

But when I update for example the first_name (in the wp_usermeta table), it updates the value on the table but then it seems to stop because I can’t get the data I’m expecting in return.

The two functions are identical:
for the display_name:

$value = sanitize_text_field( $_POST['value'] );				

wp_update_user( array( 'ID' => $user_id, 'display_name' => $value ) );

$status = array(
'status' => true,
'meggase' => ''
);

for the first_name:

$value = sanitize_text_field( $_POST['value'] );				

wp_update_user( array( 'ID' => $user_id, 'first_name' => $value ) );

$status = array(
'status' => true,
'meggase' => ''
);

does anyone has any idea why this may happen?