Samba 4, access problem?

Question

Access rights

There is a valid FS on Debian with samba 4 installed. There are 2 balls: Public and Vasya. Login/Password authorization is used to access Vasya. The config is like this:

[global]
   workgroup = WORKGROUP
   netbios name = FS01
   server string = %h server (Samba, Ubuntu)
   dns proxy = no
   log file = /var/log/samba/log.%m
   max log size = 1000
   map to guest = bad user
   security = user

[Public]
   path = /mnt/public
   force group = users
   create mask = 0660
   directory mask = 0771
   browsable =yes
   writable = yes
   guest ok = yes


[Vasya]
   comment = Only password
   path = /mnt/vasya
   writable = yes
   browsable = yes
   create mode = 0777
   directory mask = 0777
   valid users = vasya
   guest ok = no

There is also a laptop and a PC on the network, Windows 10 is installed everywhere
. I connect from the laptop to the "Vasya" folder without any authorization, since the Windows user is Vasya with the same password, but on the PC the user is completely different - Aleks and the password is different, but I still have full access to the Vasya folder. If you change "valid users = vasya", then access to the PC is terminated, requires authorization ... all the rules. Also, if you log in under a different user in Windows, it also requests authorization ... all the rules. But why the hell does a Windows user - Aleks have access to the "Vasya" folder with "valid users = vasya"??
Perhaps I set something up somewhere before, I don’t remember already, but there is only one user in the system, vasya, and in the users group, he is also the only one.