Google sitemap link shows non existing urls

[Frankie M]

Hi,

This weekend I got a message from Google Search Console that there were some indexing problems. When I checked the urls it turned out to be non existing urls.

In the sitemap link for example I see 2 url links for 1 category. One exists and the other doesn't:
<url><loc>https://www.mywebsite.nl/12-friendly url</loc><priority>0.8</priority><lastmod>2015-07-04T13:19:36+02:00</lastmod><changefreq>daily</changefreq></url>
<url><loc>https://www.mywebsite.nl/28-friendly url</loc><priority>0.8</priority><lastmod>2015-10-31T11:44:06+01:00</lastmod><changefreq>daily</changefreq></url>
Also there is a non existing index link!
<url><loc>https://www.mywebsite.nl/2-home</loc><priority>0.8</priority><lastmod>2015-06-27T12:33:05+02:00</lastmod><changefreq>daily</changefreq></url>

I cleared the cache and regenerated the sitemap. But the problem remains. We work with PrestaShop v1.6 and Google sitemap v.3.2.1.

Any clue why these old (or non existing) urls appear in the generated sitemap and how to remove them?

Kind regards,

Frank