I have a prestashop 1.6. Due a I had dirty URLs with ids, last week I bought a module to clean those URLs.
A couple of days ago, I noticed a ranking drop in Google. I have checked Google Search console and I can see that all my products and categories are marked as duplicated, (old URL with ID and new one.)
After that, I have checked the old URLs have a 301 redirection, first visually and also using tools like http://www.seoreviewtools.com/redirect-checker-tool/ It seems all 301 redirections are OK.
Is there anything else I can do?