@v-yamao-msft ,
The problem is still there, I have been in touch with the Dropbox team and the problem is not on their side.
I don't get the Root as the first Dir, the first one is "Dropbox" from there it goes into my personal folder.
I have tried to manually type in the required path but that results in an error.
I have also deleted the connection and recreate it - the same problem.
I am using Dropbox for Business, maybe that is why yours starts with Root and mine does not?
My end goal is to have sync'd folders between OneDrive and Dropbox, changes/new files/deleted files from one to the other and the other way around.