That's because your website is enabled for both
www and
non-www, and
http and
https without any redirects, and therefore you get four possible links:
http://lepetitbleausard
http://www.lepetitbleausard
https://lepetitbleausard
https://www.lepetitbleausard
X3 will add the canonical link based on the url when the page was requested, and then it will get cached. In your case, you should try to force a single access, recommended would be
https://www. This can be achieved in .htaccess, see this post
https://stackoverflow.com/a/36986520/3040364
For a simpler solution, you can use X3 Settings > Advanced > Force URL.
