Taxonomy Permalink Issue w/ Sub-Cats

Trying to make sure I’m comprehending the desired permalinks here.

You have a product_category taxonomy, with a rewrite slug of product-category.

You’re getting this structure?
mydomain.com/product-category/container/bottle/andmydomain.com/product-category/container/can/` and similar?

When you’re wanting this structure?
mydomain.com/container/bottle/andmydomain.com/container/can/` and similar?

Or is it possible that by “not work” you’re referring more to maybe those permalinks are working fine, but no content is being shown at them?

The structure that I am wanting is as followed based on your example:
mydomain.com/product-category/container/bottle/

Right now the only way I can get to it is via this URL:
mydomain.com/product-category/bottle/

Where bottle is a sub-category of parent container.

Hmm, according to posts like https://wordpress.stackexchange.com/questions/155319/how-to-include-parent-terms-in-hierarchical-taxonomy-urls, we have everything in place and as it should be. However, I was able to reproduce where /product-category/child works, but /product-category/parent/child does not.

Using the Query Monitor plugin, it seems that the parent/child version is getting interpreted as one term, not 2.

taxonomy=product_category&term=parent%2Fchild

The %2f is an encoded /

That said, setting query var to true looks like it’s working for me, so that may be the key detail going on here. Is there reason you need query var to be set to false?

No reason for query_var to be set to false, I changed it to be set to true in the attempt to get the /product-category/parent/child working but it is still throwing a 404. but /product-category/child does work.

  $labels = [
    "name" => __( "Product category", "custom-post-type-ui" ),
    "singular_name" => __( "Product category", "custom-post-type-ui" ),
  ];

  $args = [
    "label" => __( "Product category", "custom-post-type-ui" ),
    "labels" => $labels,
    "public" => true,
    "publicly_queryable" => true,
    "hierarchical" => true,
    "show_ui" => true,
    "show_in_menu" => true,
    "show_in_nav_menus" => true,
    "query_var" => true,
    "rewrite" => [  'slug' => 'product-category',
                    'with_front' => true,
                    'hierarchical' => true,
                    // 'hierarchical' => false,
                  ],
    "show_admin_column" => true,
    "show_in_rest" => false,
    "show_tagcloud" => true,
    "rest_base" => "product_category",
    "rest_controller_class" => "WP_REST_Terms_Controller",
    "show_in_quick_edit" => true,
    "show_in_graphql" => false,
  ];
  register_taxonomy( "product_category", [ "product" ], $args );

And I did attempt to clear the permalink cache.

What permalink rules are you using? Something besides “post name” for the radio button options?

When you say Post Name for the radio buttons option, this is a hierarchal taxonomy of product categories. There is a main Product post type that can have these categories assigned to it. Not sure what you mean tbh.

What I meant is basically which selection did you make when you visit Settings > Permalinks in your WP admin. Wanting to make sure I am using matching permalinks.

/wp-admin/options-permalink.php

I have “Post Name” selected.

And even with that, the permalinks with both parent and child terms aren’t working at this point?

I have the same permalinks settings and it was for me, but it’s possible something else in your install may still be interfering.