Why Microsoft still binds country and language? For example Finland is a bilingual country and the official languages are Finnish and Swedish. Yet Sweden has slight differencies for eaxample in date format. Thus choosing Swedish/Sweden is not the correct choice. Another problem comes with the fact that I am working in an international company where the software language is English. This is also reasonable due the fact that local translations are not always correct and all bug fixes are not localized nor there may be a localized version available. But since I motly write in Finnish, I definitely like to have the local date and time formats and keyboard layout. Thus please keep country, keyboard, date/time and language options separate.

Microsoft has advised us that:-

We have discussed this issue with Teams desktop client language with our technical advisor and we have found that Teams desktop client only picks up the OS language when you have set a Teams supported language in the OS and unfortunately, English Australia is not a supported language for MS Teams. Hence the users need to setup the English Australia manually in Teams desktop client and by design it will switch back to the default English UK when Teams client is signed out or uninstalled or auto updated.
Refer: https://support.office.com/en-us/article/change-your-display-language-in-microsoft-teams-293792c3-352e-4b24-9fc2-4c28b5de2db8
We request you to share a feedback and request the English Australia language in MS Teams on the user voice link mentioned below and once this request get enough votes our product engineering team will be able to include English Australia as a supported language in Teams.
http://office365.uservoice.com
Please let us know if provided information answers your questions and if we can proceed with the closure of this service request.

Australian English is supported (else you would not be able to select it), but every time the application updates, it reverts back to American English. Please fix Teams so it maintains the language when set the first time the application is installed!

Issue Summary:
Switching from a Tab to Chat / Teams / Other Tabs causes the Tab to close, causing you to have to reopen the Tab (actually having to navigate to it again inside the team). This will reload the tap and all content before the Switching will be lost.

Issues:
1. Tabs open in Team gets reset - when switching between Teams in Team View
2. Tabs reload - when switching between Chat and Team View
3. Content (edits, files etc) on Tab gets lost (Happens both for to Issue 1 and 2)
4. It makes you re-sign-in to Planner, Jira or whatever third-party tab you were using

Enhancements requested:
1. Tabs should stay open in the related Team - having to navigate and reopen a tab every time is very bad for workflow (Relates to Issue 1)
2. Tabs should be kept in memory - Reloading the tab every time is Very slow (Relates to Issue 1 and 2)

For us the main issue is that we lose edits, files, data etc when we navigate away from a tab to a chats or a different tab as the original tab reloads. We really can not be loosing data.

I see many of other issues on here that are related? I will list them here and ask that they get merged.

I will also comment on all the other issues and ask that people come here to vote and list more issues so that I can keep this issue updated with requests.