To fix squid authentication we need set permissions in /var/lib/samba/winbindd_privileged folder:
Set user root and group for winbind:
chown root:proxy /var/lib/samba/winbindd_privileged -R
or
chown root:squid /var/lib/samba/winbindd_privileged -R
Set folder permission
chmod 750 /var/lib/samba/winbindd_privileged -R
and restart winbind and squid
systemctl restart winbind
systemctl restart squid
