I have a site setup with translations on SS 2.3.3 that is working as it should. I used the exact same code from mysite/_config.php for a new 2.3.5 and now it is not working. In the CMS the language dropdown is present with the default language only. When on the translations tab of a Page the New Translation Dropdown is empty. Here is the portion of code from _config.php regarding translatable:
In my setup, which is working, I donâ€™t use Translatable::set_allowed_locales($allowed_locales); but i18n::$common_locales = $allowed_locales;. I know that it doesnâ€™t mean the same thing, but maybe it can help.
You should look in CMS code where the list New Translation is coming from, thereâ€™s maybe a bug somewhere.