Yellowfin does not switch to Regional Language report views.
One of our customer has a test system where users work with german locale settings.
One day they noticed that the field names in the views were only presented in english (compare attached doc). The reports themself were also a mix of mostly english field labels.
We did some troubleshooting and noticed that the users did not have the ability to change their preferred language. The menu in the settings was just not there.
We checked in the default tenant. We found out that multi-language support was active but there were no actual languages in the list. So the customer added english and german (for all tenants) and that allowed the users to see the language menu again and chose german as their preferred language.
But the German language is shown partially in the console. ISO language code is enabled in the smart reporting DB, customer is on 7.3 2018 Nov build