Polylang causes empty woocommerce brand archive

On a customer site I have the WooCommerce Brands extension installed. This extensions registeres this taxonomy:

register_taxonomy( 'product_brand',
	        array('product'),
	        apply_filters( 'register_taxonomy_product_brand', array(
	            'hierarchical' 			=> true,
	            'update_count_callback' => '_update_post_term_count',
	            'label' 				=> __( 'Brands', 'wc_brands'),
	            'labels' => array(
	                    'name' 				=> __( 'Brands', 'wc_brands' ),
	                    'singular_name' 	=> __( 'Brand', 'wc_brands' ),
	                    'search_items' 		=> __( 'Search Brands', 'wc_brands' ),
	                    'all_items' 		=> __( 'All Brands', 'wc_brands' ),
	                    'parent_item' 		=> __( 'Parent Brand', 'wc_brands' ),
	                    'parent_item_colon' => __( 'Parent Brand:', 'wc_brands' ),
	                    'edit_item' 		=> __( 'Edit Brand', 'wc_brands' ),
	                    'update_item' 		=> __( 'Update Brand', 'wc_brands' ),
	                    'add_new_item' 		=> __( 'Add New Brand', 'wc_brands' ),
	                    'new_item_name' 	=> __( 'New Brand Name', 'wc_brands' )
	            	),
	            'show_ui' 				=> true,
	            'show_in_nav_menus' 	=> true,
				'capabilities'			=> array(
					'manage_terms' 		=> 'manage_product_terms',
					'edit_terms' 		=> 'edit_product_terms',
					'delete_terms' 		=> 'delete_product_terms',
					'assign_terms' 		=> 'assign_product_terms'
				),
	            'rewrite' 				=> array( 'slug' => $category_base . __( 'brand', 'wc_brands' ), 'with_front' => false, 'hierarchical' => true )
	        ) )
	    );
	}

This taxonomy is NOT listed under the Polylang setting ‘Custom taxonomies’,
Which is odd but probably (?) not a problem in this case because we actually don’t want to activate translations for this brand taxonomy (it’s language nutral).

But when Polylang is activated the brand archive page of every brand is empty. If Polylang is deactivated every brand lists it’s products.

For example, this URL should list about 25 products but instead with Polylang active it shows only a message that no producst matching the criteria where found:

So my actual question is:
How can I force Polylang to not interfer with this taxonomy?

The installed Polylang version is 1.7.9 (latest), the site is fully up to date (core/plugins).