Hi @Chidchanok Monroek ,
Can you uninstall the Teams client and reinstall one?Or delete the cache and see if that could work.
And is your account the guest account of an organization or licensed user account?
If it's a guest account, you may ask the Teams admin to regain guest access.
And anothing thing is you can try using Safari to login to Teams for web to test you account.
Best regards,
Lou
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