[Samba] Samba shares are slow after 4.2.11 upgrade

[Daniel Carrasco Marín]

Hi, first of all i'm sorry for my english.

i'm using sernet packages to keep updated my file server, but after the
latest update it becames very slow listing and accesing to files... For
example, a thunderbird profile from networks takes about 1 minute to load.
Now the profile takes about 20 minutes and the program still loading...
I've not changed any configuration on server and i don't know what can be
the problem.

After the update i was using Samba 4.2.9 and all was working without
problem: Is there any way to downgrade to that version?.

Here's my smb.conf:
[global]
        netbios name = serverName
        security = ADS
        workgroup = DOMAIN
        realm = DOMAIN.DOM

        log file = /var/log/samba/%m.log
        log level = 1

        dedicated keytab file = /etc/krb5.keytab
        kerberos method = secrets and keytab
#        encrypt passwords = yes

    idmap cache time = 604800
        idmap config *:backend = tdb
        idmap config *:range = 40000001-60000000
        idmap config DOMAIN:backend = ad
        idmap config DOMAIN:schema_mode = rfc2307
        idmap config DOMAIN:range = 500-30000000


    winbind nss info = rfc2307
    winbind trusted domains only = no
    winbind use default domain = yes
    winbind enum users  = Yes
    winbind enum groups = Yes
    winbind refresh tickets = Yes
    winbind expand groups = 4
#    winbind normalize names = Yes
    winbind offline logon = yes

    vfs objects = acl_xattr
    map acl inherit = Yes
    store dos attributes = Yes

    client max protocol = SMB2_22

    #Logs
    log level = 1
    syslog = 0
    log file = /var/log/samba/%m
    max log size = 50


    # Stackable VFS modules
    #vfs objects = full_audit recycle
    vfs objects = recycle

    # Audit
    #full_audit:prefix = %u|%I|%m|%S
    #full_audit:success = mkdir rename unlink rmdir pwrite pread connect
disconnect
    #full_audit:failure = none
    #full_audit:facility = LOCAL7
    #full_audit:priority = NOTICE

    #Papelera
    recycle:config-file = /etc/samba/recycle.conf
    recycle:repository = /server2/share/Papelera
    recycle:keeptree = Yes
    recycle:versions = Yes

[public]
    path = /server2/share/public
    read only = No
    guest ok = Yes
    create mask = 0666
    directory mask = 0777


[home]
      path = /server2/share/home
      writable = yes
      read only = no
      browseable = yes
      create mask = 0600
      directory mask = 0700


I've added the "client max protocol = SMB2_22" and commented the "Encrypt
passwords" to check.

Thanks.