I have tried all possible ways..... from here and from
https://forum.rclone.org/t/dropbox-no-members-read
Saddly, rclone is no longer working with Dropbox business. So bad...
And the issue is clearly coming from Dropbox themselves.
Shame on them...
Finally I have use Multcloud and setup an FTP on my NAS-Rpi . Multcloud does work very well with DropBox business Teams folders. So I use Multcloud for accessing Dropbox business and then backup all my Team folders to my NAS-Rpi via SFTP (SHH ftp actually). I did not want to do that as I have now to watch and protect some ports on my Rpi-NAS and on my router... but this is life...