While attempting to get symfony translations to work correctly I noticed they would not work with the /ja site access I created for the jpn-JA language I created. I have a siteaccess for each language and I can see through the profiler that each get request returns the appropriate _locale variable except for Japanese.

I installed/configured a fresh copy of 16.02 and created 3 new languages and siteaccess (site, fr, ja) | (eng-GB, fre-FR, jpn-JA) languages.

My ezpublish.yml file is:

1. Siteaccess configuration, with one siteaccess per default
   siteaccess:
   list: [site, fr, ja]
   default_siteaccess: site
   match:
   URIElement: 1

1. System settings, grouped by siteaccess and/or siteaccess group
   system:
   site:
   languages: [eng-GB]
   fr:
   languages: [fre-FR, eng-GB]
   ja:
   languages: [jpn-JA, eng-GB]