I upgraded to Insync 3 and all my junction points using a UNC path to network shares were moved to “New folder” folders on Google Drive. Distant files on the server were uploaded in these “New folder” folders and deleted from my server.
So I stopped Insync, downloaded these files back from these “New folder” folders that were created on Google Drive (several GB) and put all of them back on the server. Fortunately, I recovered everything.
Now, I am not very confident that I can or should use junction points anymore.