1. Add new ger-DE language.
2. Add new ger Site Access:

           list:
               - site
               - ger
               - corporate
           groups:
               site_group: [site, ger]
               corporate_group: [corporate]
           default_siteaccess: site
   
   ---------------------------------------------------
   
           site:
               languages: [eng-GB, ger-DE]
           ger:
               languages: [ger-DE, eng-GB]
   
   ---------ibexa_admin_ui.yaml-------------------
               page_builder:
                   siteaccess_list: [site, ger]
   

3. Uncheck the "Always available" flag from the Landing Page Content Type.
4. Create a new Landing Page content in eng-GB language.
5. Place:

           dump($resolvedSiteAccess);
   

   at the bottom of the previewAction in vendor/ibexa/page-builder/src/bundle/Controller/PageController.php

6. Translate previously created Landing Page to ger-DE language.

Result:
Dumped Site Access is site.

Expected result:
Dumped Site Access should be ger.

Note:
This ticket is a direct follow-up of https://issues.ibexa.co/browse/IBX-5359. The offered solution that was merged in the mentioned ticket won't work as Page Builder matching system was rewritten in v4.5.