[regression] Core language switcher disappeared in Drupal 9.5.5

Problem/Motivation

After upgrading from Drupal 9.5.4 to 9.5.5, the language switcher block disapeared entirely on all pages.
This is caused by https://www.drupal.org/sa-core-2023-003

Maybe it just happens with our language negociation configuration.

I debugged the issue and recognized that the result object of the new URL access check has the correct value. But it is not taken into account.

Steps to reproduce

Proposed resolution

Remaining tasks

User interface changes

API changes

Data model changes

Release notes snippet