Sharing Folder Exposes File System to Linux Computer

I would like to share a project folder between my macOS and another Linux computer on my local network, but when I do it exposes my entire file system to the Linux computer, with read/write access.

I followed all the steps in setting up a shared folder, starting in macOS. Please read carefully to understand what options I enabled and disabled:

• File Sharing: On.
• Allow full disk access for all user: Off.
• Shared Folders: Removed everything but the one folder I want to share.
• Shared Folder Users: User - RW, Staff - R, Everyone - No Access.
• Shared Folder Ctrl click: Guests off, SMB Encrypted on, Time Machine off, Limit backups off.
• Shared Folders Options ... : SMB File Sharing - on, Windows File Sharing - On (Selected myself as user)

Even though full disk access for all users is disabled and only the one shared folder is specified in the Shared Folders menu, the entire macOS disk is mountable by means of:

Linux

• File manager (like Finder).
• Network.
• Visible in Network is [myuser].Mac.mini.
• Visible in [myuser].Mac.mini is [user], Macintosh HD and Shared Folder
• Click on any of those, they mount and allow me to:
• [user] - rwx
• Macintosh HD | Root system rx | User directory rwx.
• Shared Folder rwx.

What option am I missing? I really only want the Shared Folder specified in macOS to be mountable for shared rwx permissions on the Linux system and nothing else.

Looking forward to your thoughts!