Date and Language Settings in Teams

I use Teams in a browser and the language settings won't stay. I change them to Swedish, Teams requires a new start, I start it again in the browser and get the right language. Next day or week the language is set to English again. I don't recognise it immediately, because not everything is in Swedish. When I do have the Swedishlanguage on, I still see some things in English, like "Class Notebook", which should be "Anteckningsbok för klassen".
And don't suggest I should use the desktop app instead of the browser. The desktop app can't have several teams opened at the same time.
And don't suggest I should set my Windows or my browser to have a particular language setting! I need Teams to have one language setting. I need Windows to have another language setting. I need the browser to have a third language setting. I live a multilingual life! I'm the one who decides what language I want. I may use whatever language wherever. But when I log in to Teams, I expect Teams to remember what language I prefer in Teams. I don't expect Teams to use same language as my browser! If you disagree, read again the last chapter but slower.