This is normal behavior, the alias is not part of the SEO URL generation. That means, the alias will not be loaded via the router. Just add it by yourself: index.php?[...]&id=40-john-doe

Problem: Search engines count the two different links to the same content as duplicate content.
Ehhh...no

Hi @bembelimen,
thanks for your quick answer.
However I am wondering, why the router generates different URLs for the same content in articles (/menu-item/child-menu-contactlist/40) and in the contact list view (menu-item/child-menu-contactlist/40-john-doe).
The problem of duplicate content is, that the canonical tag (rel=canonical) in the HTML also shows the two different values, if I visit the contact page from the different locations. By this we tell Google, that these two URLs contain different information. Google sees, that the content is identical and will rate this as duplicate content: https://support.google.com/webmasters/answer/66359?hl=en
I solved my problem for now, by manually manipulating the link id-parameter in the HTML view of the article from (index.php?[...]id=40[...]) to (index.php?[...]id=40:john-doe[...])

in 3.5.1 joomla core will not generate a canonical URI, except when you add a different canonical domain in the sef system plugin domain field. See #9565 for more info.

If anyone else has the same "issue". Here's a workaround:
If you use JCE, there are two different ways to link a contact.

1. Link Browser: Tree, where you can select contacts by Category. These links only contain the article-id without the alias. index.php?[...]id=40[...] leads to /menu-item/child-menu-contactlist/40
2. Link search: Search field, where you can look for the contact name. These links contain the article-id + the alias and the alias of the category. index.php?[...]id=40:john-doe&catid=10:persons[...] leads to menu-item/child-menu-contactlist/40-john-doe

I would for now use the search to get the contact alias into the link, but remove the category alias to keep the dependencies on duplicate information as low as possible.

@jwiesel

• I set a Link in Article-Fulltext index.php?option=com_contact&view=contact&id=33:super-admin&catid=4&Itemid=107
• Global Configuration: Search Engine Friendly URLs is Yes
• Frontend: Article-Link is contacts/super-admin

Article-Options: Tab Integration: URL Routing "Modern", Remove IDs from URLs: "Yes"

Test on:

Joomla! 3.7.0-staging
macOS Sierra, 10.12.3
Firefox 50.1.0
PHP 7.0.4
MySQLi 5.5.53-0

This will be fixed in #14322