Can't open the feedback itself, but facing the same issue and upvoted your topic here. And we are also having complaints from customers. For them, when they have not added any preferred language is very hard to understand how to change the app language as it's not visible on app settings. For those who have added a preferred language, they most probably already have the app in the correct wanted language and if needed to change, then they have this option under app settings also. They can pick any language - even language that is not under selected system preferred languages. If Apple would show language selection ALWAYS under the app settings, then it would fix the problem.

Yes, it's super annoying. :(