Can you confirm that you have installed both of these packages?
samba36-server
Description of this package:
The Samba software suite is a collection of programs that implements the SMB protocol for UNIX systems, allowing you to serve files and printers to Windows, NT, OS/2 and DOS clients. This protocol is sometimes also referred to as the LanManager or Netbios protocol.
luci-app-samba
Description of this package:
Network Shares - Samba SMB/CIFS module
I guess you have this installed, because you are able to configure it through the webinterface (luCi)
If yes, could you post your smb.conf file.
How to get this.
Step 1: SSH to your Turris
Step 2: type
cat /etc/samba/smb.conf
Copy and past what you have copied in the post.