Hi
Sorry yes an external tool: SeRanking (https://online.seranking.com)
All of those links are actually the same page but reported as different pages with all the implications as mentioned above.
So first, that's not really a problem from an SEO standpoint. Search engines won't really care about that because it's only 3 pages, with roughly the same content. Ideally, there should be a canonical there indeed but I'm not sure why 4SEO is not generating them. Did you disable anything in the Pages | Settings configuration?
- What I noticed is that you "Startseite" menu item goes to https://www.[redacted].at/index.php instead of https://www.[redacted].at/ so that's something you must fix, you're creating a visible duplicate here.
- also I think you should start using URL rewriting in your Joomla configuration. All your URLs are using an /index.php/ bit such as https://www.[redacted].at/index.php/menuausbildungen/menulsb and that's not best both for URL readibility but also because it will have side effects, for instance on some 404s handling.
(like my ticket before where different tools report different http-Status codes for the 1px images 4Seo creates. One report 200 and one 4xx and but tool-provider claims they are right - the user is lost in translation ;) (I have chosen to ignore that 4xx-Problem.
And rightly so. These are non-problems.
Best regards
Yannick Gaultier
weeblr.com / @weeblr