here is the case :
We have a Windows DFS Tree with a DFS root : \\SERVER\DFSROOT
In this root, we have multiple "symlinks" (redirections to other folders on other shares).

Example :

We add the \\SERVER\DFSROOT as net folder server
We add a net folder directly mapping to \\SERVER\DFSROOT

If the proxy user has no rights on FOLDERA, but has rights on FOLDERB, FOLDERC, then the folder mapped to "\\SERVER\DFSROOT" displays nothing in the WebUI.

Looking at the logs we have something like :

[XTCOM]: ERROR:thread_handler: request processing failed
[XTCOM]: ERROR:send_status: sending status ret: -1
[XTCOM]: ERROR:Trustees::isTrusteeInherited Could not get attributes for [smb://server/dfsroot/foldera] 2: No such file or directory

It seems the synchronization process stops one the first error, not letting use acces the other folders.

If we directly map the "\\SERVER\DFSROOT\FOLDERB", it can synchronize, and then displays the content.

Bug or "Built-In feature" ?

We might want to prevent the proxy user to access some folders in a shared tree ....