Upgrade to 2.8.8.1 results in “Cannot save pod to collection”

Hi all,
we use a pod as taxonomy (the “Dokumentart” column in https://www.eftcd.de/fachliteratur) in combination with ACF Pro.
We run Pods 2.7.26 and the pod is registered in functions.php, see below for the function.
When we upgrade to Pods 2.8.8.1 the error “Cannot save pod to collection” is thrown. Removing the registration from functions.php resolves the error and removes the taxonomy.

Any idea how to progress from here is welcome…
Thanks a lot!
—
function register_my_pods_config_4127361() {

$pod = array (
‘name’ => ‘dokumentart’,
‘label’ => ‘Dokumentart’,
‘description’ => ‘Dokumentart’,
‘type’ => ‘taxonomy’,
‘storage’ => ‘meta’,
‘show_in_menu’ => ‘1’,
‘label_singular’ => ‘Dokumentart’,
‘public’ => ‘1’,
‘show_ui’ => ‘1’,
‘hierarchical’ => ‘1’,
‘label_add_new_item’ => ‘Neue Dokumentart zufügen’,
‘label_new_item_name’ => ‘Neue Dokumentart-Name’,
‘label_edit_item’ => ‘Dokumentart bearbeiten’,
‘label_update_item’ => ‘Dokumentart aktualisieren’,
‘label_view_item’ => ‘Dokumenart anschauen’,
‘label_all_items’ => ‘Alle Dokumentarten’,
‘label_search_items’ => ‘Dokumentart suchen’,
‘label_popular_items’ => ‘popul?re Dokumentart’,
‘label_parent_item’ => ‘übergeordete Dokumentart’,
‘label_not_found’ => ‘Nicht gefunden’,
‘label_items_list_navigation’ => ‘Dokumenart-List Menu’,
‘label_items_list’ => ‘Dokumentart-List’,
‘label_separate_items_with_commas’ => ‘Trenne Dokumentarten mit Kommas’,
‘label_add_or_remove_items’ => ‘Dokumentart zufügen oder l?schen’,
‘label_choose_from_the_most_used’ => ‘W?hle aus popul?re Dokumentarten’,
‘rewrite’ => ‘1’,
‘rewrite_with_front’ => ‘1’,
‘rewrite_hierarchical’ => ‘1’,
‘capability_type’ => ‘default’,
‘capability_type_custom’ => ‘dokumentart’,
‘query_var’ => ‘0’,
‘sort’ => ‘0’,
‘built_in_post_types_acf-field’ => ‘0’,
‘built_in_post_types_acf-field-group’ => ‘0’,
‘built_in_post_types_cs_footer’ => ‘0’,
‘built_in_post_types_cs_global_block’ => ‘0’,
‘built_in_post_types_cs_header’ => ‘0’,
‘built_in_post_types_cs_template’ => ‘0’,
‘built_in_post_types_cs_user_templates’ => ‘0’,
‘built_in_post_types_custom_css’ => ‘0’,
‘built_in_post_types_customize_changeset’ => ‘0’,
‘built_in_post_types_mec-events’ => ‘0’,
‘built_in_post_types_mec_calendars’ => ‘0’,
‘built_in_post_types_oembed_cache’ => ‘0’,
‘built_in_post_types_page’ => ‘0’,
‘built_in_post_types_post’ => ‘1’,
‘built_in_post_types_user_request’ => ‘0’,
‘built_in_post_types_wp_block’ => ‘0’,
‘built_in_post_types_wpcf7_contact_form’ => ‘0’,
‘built_in_post_types_attachment’ => ‘0’,
‘menu_location’ => ‘default’,
‘menu_position’ => ‘0’,
‘show_in_nav_menus’ => ‘1’,
‘show_tagcloud’ => ‘1’,
‘show_tagcloud_in_edit’ => ‘1’,
‘show_in_quick_edit’ => ‘1’,
‘show_admin_column’ => ‘0’,
‘pfat_enable’ => ‘0’,
‘pfat_run_outside_loop’ => ‘0’,
‘pfat_append_archive’ => ‘append’,
‘rest_enable’ => ‘0’,
‘read_all’ => ‘0’,
‘write_all’ => ‘0’,
‘menu_name’ => ‘Dokumentart’,
);

pods_register_type( $pod[ ‘type’ ], $pod[ ‘name’ ], $pod );

}
add_action( ‘init’, ‘register_my_pods_config_4127361’ );`

The page I need help with: [log in to see the link]