Jing, I modified your sync files as described: removed the /TempData/ from the RootFolder on the server and added ServerPath=/TempData/ to the client and it works fine. The modified files are below. I had to create the folder csentry/TempData on the server tablet (or you could add CreateServerPath=/TempData/ to the client). If you get different results with these files please send me the synclog.txt file from the csentry directory.
[SyncFile]
Version=CSPro 6.1
AppName=FromInterviewer
Description=Receive data files from interviewer, on supervisor device
DeviceName=002: Jon
RootFolder=/storage/emulated/0/csentry/
[Connection]
Type=BluetoothServer