Samba - Password protected share

I've configured a SAMBA server with 2 shares, one is public and the other is private, which is password protected.

The server works brilliantly, I can access both shared folders, and the password protected one asks for login (user and password), which is fine.

My issue is, is I login to the password protected folder the it stays accessible to everyone on the same windows machine.

Is there any thing I could do, so that I could lock the private folder before I leave the machine? or is it possible to add a timeout so that the folder would be locked after e.g. 8 hours?

We are a small company and the laptops are there to be used by several people, so it would be fantastic if I could lock the password protected folder after I finished with the laptop.

We use Ubuntu 18.04 and about all our machines are windows 10 machines.

our samba config is as follows:

#======================= Global Settings #=====================================

[global]workgroup = WORKGROUPserver string = PRIMARY %v netbios name = PRIMARYdisable netbios = Yessecurity = usermap to guest = bad user dns proxy = no 

#-----------------secure-passowrd----------

[DATA]path = /media/DATAvalid users = @technicalguest ok = nowritable = yesbrowsable = yes

Many thanks

M