Drupal Community Portal

Good day everyone. My co-worker and i are wondering. We have a new website that is a exact copy of the first depreciated one. Now the new site is not capable of doing a content "undefined language" when our prior website was doing it.
The new site was not imported or migrated, it was build from a fresh install. All of the modules and languistic options are exactly the same in both. The problem is the new website refuse to create a content based on "undefined language" and always create with the default that is english. We want "undifined". Witch way to go first and why it is not like our old website even if configured the same.
Thank you.