Hello,
Thank you for contacting Rank Math and bringing your concern to our attention. I’m sorry for any inconvenience this issue may have caused you.
Upon enabling the strip category base option, the old URL should automatically redirect to the new structure.
Could you please share the affected URL/s so we can check? Also, please share the screenshot of the issue in your Google Search Console. You can upload it using this tool and add the link here.
Looking forward to helping you.
Thank you.
https://ibb.co/q0LbSvY
https://ibb.co/bQWJhG6
sorry for the delay!
As you can see in the images, the product page is not indexed because it is the redirect (albeit with the appropriate canonical). Neither page is indexed.
Is there a possibility to restore “shop” in urls and categories without getting 404 errors?
Hello,
Currently, the current URL for your product is https://www.4fishing.it/mulinelli/frizione-anteriore/mulinello-fuego-lt-2020-daiwa/ and it is already indexed in the SERPs:

The URL that is not indexed is incorrect and shouldn’t be submitted to your GSC account as you are using product categories in the permalink structure and our plugin is submitting the correct URLs via the sitemap.
If you don’t want to include the categories in the URL, you will have to change your permalink structure from WP Dashboard > Settings > Permalinks. However, since the URLs are already indexed, it is not recommended to do that.
Hope that helps. Let us know if you need any other assistance.
Hello,
Since we did not hear back from you for 15 days, we are assuming that you found the solution. We are closing this support ticket.
If you still need assistance or any other help, please feel free to open a new support ticket, and we will be more than happy to assist.
Thank you.