TYPO3 Core

In the definition of languages via the site configuration, it is possible to deactivate specific languages in the frontend via the configuration property enabled. Regardless of the value of the configuration property, the SiteMatcher registers the base as a route, which means that if the same base is used by several languages (e.g. an activated and a deactivated language), it is not clear for which language the route will be registered. And in the worst case, the activated language is not available in the frontend, as the route is already used by the non-enabled language.

As it is described in the documentation (https://docs.typo3.org/m/typo3/reference-coreapi/12.4/en-us/ApiOverview/SiteHandling/AddLanguages.html#confval-sitehandling-addinglanguages-enabled) that the visibility in the frontend is influenced by the configuration property enabled, the expected behavior should be that the route is only registered for enabled languages.