In this instance I’m trying to use the multiple language localization options of the platform to provide mirrored versions of the same course but with the foroums in multiple languages.
Have you tried setting the language at the course level and then create your forum?
This is on the properties tab.
I think the issue here is they are trying to have one forum facilitate multiple languages not just set it to a different one. Not sure this is easily possible in the current setups, following for someone to happily prove me wrong.