Up-to-date Windows 10 Pro and Remote Utilities 18.104.22.168 on the host and remote computers.
These files located a root directory (D:\) unexpectedly and unwantedly show in the local (left) half of the File Transfer mode, whereas they do not when that directory is viewed in Windows File Explorer.
Is this a bug or is there something that has to be set to hide these files?
No this is not a bug. As Remote Utilities is an admin tool/utility, even the protected system folders and files are supposed to be visible in the File Transfer mode. Currently, there is no way to hide them, although we may add this suggestion to our wish list.
Don't hesitate to ask me if you have other questions.