Hi
1 - Good that you noticed this by looking at the search console but it's always best to first look at your site and your pages.
I'm not surprised several pages in your sitemap are not indexed: the sitemap file contains multiple duplicates and thin content pages:
https://www.xxxx.com/emplois/casting?limit=20&start=40, https://www.xxxx.com/en, etc
You should review it and possibly remove it as your site is simple. Just make sure all the pages can be crawled.
2 -
What i mean is that i feel strange that Google are indexing more frequently the contents from my amp pages rather than those for desktop : you can see the difference between these two files (sitemap-indexed and amp-indexed).
It does not crawl more often your AMP pages than your desktop pages. That's not how it works. Google indexes your standard pages. If you have an AMP version as well, then it also notice that this AMP version exist. But it does not "index" it. It indexes the "main" page, the standard one and just displays the AMP version in search results on mobile.
>> The number you see on that page (Envoyée et indexée) is NOT the number of pages indexed on your site. It's only the result of your sitemap processing. Google crawls and decide on which pages to index by themselves. The sitemap is just an indication you give them, a hint but they mail well not take it into account many times, especially on smaller, simpler sites.
For the first, you can see that the last time that Google was crawled this menu is the 1 april! where for the amp content it crawl more frequently (last time was the7 april)
Again, you are just talking about your sitemap here. This does not reflect what Google is crawling and indexing on your site.
3 -
Important: it's been already some times now that Google (for most sites) is using their mobile robot to index sites. It's celled "mobile-first indexing". Basically your desktop pages are not really taken into account, at least not for indexing.
You should also not mistake "mobile version" and "amp version". AMP is
NOT your mobile version. You have a mobile version and then you also have an AMP version. The AMP version is not used for indexing or ranking. It's only used for display in search results.
Your
mobile version is used for indexing and ranking.
4 - In conclusion: you do not have any problem. All is working fine (yes, I checked that the AMP pages have a proper canonical to the standard version). Do not add any redirect or any canonical, you are going to break something.
Best regards