Custom field SELECT is not saving or displaying value.

Hello,

Can you please share your callback function? I've tested to create a callback function like this

function admin_get_exteriors_from_options() {
    return [
        'red'       => 'Red',
        'green'     => 'Green',
        'blue'      => 'Blue'

    ];
}

And it works as well on my local site. Here is the field group generate code:

    $meta_boxes[] = [
        'title'    => __( 'my custom fields', 'your-text-domain' ),
        'id'       => 'my-custom-fields',
        'priority' => 'low',
        'fields'   => [
            [
                'name'   => __( 'Group', 'your-text-domain' ),
                'id'     => $prefix . 'group_po9o7bashyc',
                'type'   => 'group',
                'fields' => [
                    [
                        'name'    => __( 'Select', 'your-text-domain' ),
                        'id'      => $prefix . 'select_34gpvjxnu6a',
                        'type'    => 'select',
                        'options' => admin_get_exteriors_from_options(),
                    ],
                ],
            ],
        ],
    ];