Samba does not accept new user

I try to configure a samba share with dedicated user. This user should not be able to login, and is only used to access the share.
So, do the following:
Create the user
sudo adduser sr
Enter simple password
Add it to samba
sudo smbpasswd -a sr
Enter the same password
Enable the user (I guess it is not necessary)
sudo smbpasswd -e sr
Create the folder to share /storage/rsh and assign permissions
sudo chown sr:sr /storage/rsh
sudo chmod -R 755 /storage/rsh
Add the records to /etc/samba/smb.conf
[rsh]
path = /storage/rsh
Restart samba
sudo service smbd restart

When I try to coect to this share using any client (from Android, Windows and even Nautilus on the same computer) it keeps asking me user and password, and does not accept what enter.

Interestingly, if I add myself (existing user) as a samba user, and try to coect using this account, the share becomes accessible and works well (I have read permissions).
sudo smbpasswd -a at
sudo service smbd restart

I do not understand what can be the difference between me (at) and the new user I create (sr) so that the last one does not work in samba.