Rose 201e kept logging out after logging into cloud WebDAV/FTP, why?

Hi, I was trying to get my Rose amplifier to log into my NAS’ FTP/WebDAV (I have both) services, but when I try it, the amplifier kept saying that the folder is empty (even though it wasn’t). This is abnormal as logging into the FTP service in other devices do list out all files and folders. Why is that happening?

From what I’ve seen from the NAS, it seems like the Rose amplifier logged out just after when it logs in. (check attached)

Let me know if I am doing anything wrong or is there a workaround to this, thanks.