custom – Magento 2.3.4 plugin sitemap does not work


I had a plugin that worked on version 2.2.2 but it doesn't work on 2.3.4. It seems so collectSitemapItems() Method doesn't even fire in native Magento when I do print_r('Die');die;

public function collectSitemapItems()
    {
        print_r('Not firing');die;
        /** @var $helper MagentoSitemapHelperData */
    ...

But it is printed under protected methods _initSitemapItems()

/**
     * Initialize sitemap
     *
     * @return void
     */
    protected function _initSitemapItems()
    {
     print_r('Working Here');die; 
    ...

My plugin has afterCollectSitemapItems() Method:

public function afterCollectSitemapItems(
        Sitemap $subject
    )
    {
        print_r('Not firing here either');die;

My plugin di.xml:

 
   
 

Any ideas why this doesn't work anymore?