This extension adds console commands to be able to regenerate;

• a product rewrite URL based on its url path;
• a category rewrite URL based on its url path;
• a category URL path based on its URL key and its parent categories.

Using Composer;

composer require elgentos/regenerate-catalog-urls
php bin/magento setup:upgrade

Or download and copy the Iazel directory into app/code/, enable the module and run php bin/magento setup:upgrade.

Usage:
 regenerate:product:url [-s|--store="..."] [pids1] ... [pidsN]
 regenerate:category:url [-s]--store="..."] [cids1] ... [cidsN]
 regenerate:category:path [-s]--store="..."] [cids1] ... [cidsN]

Arguments:
 pids                  Products to regenerate
 cids                  Categories to regenerate

Options:
 --store (-s)          Use the specific Store View (default: 0)
 --help (-h)           Display this help message

Eg:

# Regenerate url for all products and the global store
php bin/magento regenerate:product:url

# Regenerate url for products with id (1, 2, 3, 4) for store 1
php bin/magento regenerate:product:url -s1 1 2 3 4

url_key contains the key, like joust-duffle-bag for the product "Joust Duffle Bag". The url_path is generated by taking the url_key and adding the suffix (which for products is stored in catalog/seo/product_url_suffix and defaults to .html). So the url_path would by default become joust-duffle-bag.html. It also adds the category slugs of the parent categories so the url_path might become bags/joust-duffle-bag.html. However, the use of url_path has been deprecated since early Magento 2.1 versions (see here). If you are running on a recent Magento 2 version, you can safely delete those values by running DELETE FROM catalog_product_entity_varchar WHERE attribute_id = (SELECT attribute_id FROM eav_attribute WHERE attribute_code = 'url_path' AND entity_type_id = 4).

This is probably due to url_path values in the database. Since these aren't updated anymore, but they are still present, the data may be out of sync. See these issues. The easiest fix is to delete the url_path values from the database (only if you are running >2.1). Here's a quick query; DELETE FROM catalog_category_entity_varchar WHERE attribute_id = (SELECT attribute_id FROM eav_attribute WHERE attribute_code = 'url_path' AND entity_type_id = 3);.

If you see this error, you have duplicate url_key values (within a store) in catalog_product_entity_varchar. You can use this extension to check those (and you need to fix them manually): baldwin/magento2-module-url-data-integrity-checker.