[Plugin:Types] Child Theme Functions – Default Post Format to Custom Post

Hi, i’m losing my mind..

I have the theme TA Music.
I’m trying to set a default format for a custom post.
custom post is made by using Types plugin.
I’m using this code to set the default post format:

function slimline_default_post_format( $format ) {
    global $post_type;

    switch( $post_type ) {
        case 'post_type_1' :
            $format = 'aside';
            break;
        case 'post_type_2' :
            $format = 'quote';
            break;
    }

    return $format;
}

I have added it to my child themes function.php (my_functions.php).

But I dont get any results… At all.
I have tried several things now and a lot of different kind of code. Just to get some kind of result.
I’m thinking that my child themes function / my_functions.php is not linked correctly from my parent theme.

I pasted this code at the bottom at the parent themes functions.php

include_once( get_stylesheet_directory() . '/lib/my_functions.php' );

Is there a way to test if my child theme my_functions.php is working probably?
Or is there something wrong with the codes?


Thanks!