soon after starting dovecot these errors start to appear. I will send the first errors after doing a service dovecot start

    Jul 15 10:08:16 box5 dovecot: pop3: Error: conn unix:/run/dovecot/stats-writer (pid=4137823,uid=0): Timeout waiting for handshake response
    Jul 15 10:08:16 box5 dovecot: managesieve: Error: conn unix:/run/dovecot/stats-writer (pid=4137823,uid=0): Timeout waiting for handshake response
    Jul 15 10:08:16 box5 dovecot: imap: Error: conn unix:/run/dovecot/stats-writer (pid=4137823,uid=0): Timeout waiting for handshake response
    Jul 15 10:08:16 box5 dovecot: auth: Error: conn unix:/run/dovecot/stats-writer (pid=4137823,uid=0): Timeout waiting for handshake response
    Jul 15 10:08:16 box5 dovecot: imap-login: Error: conn unix:/run/dovecot/stats-writer (pid=4137823,uid=0): Timeout waiting for handshake response   
    Jul 15 10:08:16 box5 dovecot: lmtp: Error: conn unix:/run/dovecot/stats-writer (pid=4137823,uid=0): Timeout waiting for handshake response
    Jul 15 10:08:16 box5 dovecot: imap-login: Error: conn unix:/run/dovecot/stats-writer (pid=4137823,uid=0): Timeout waiting for handshake response   
    ul 15 10:08:16 box5 dovecot: imap: Error: conn unix:/run/dovecot/stats-writer (pid=4137823,uid=0): Timeout waiting for handshake response   
    Jul 15 10:08:16 box5 dovecot: managesieve: Error: conn unix:/run/dovecot/stats-writer (pid=4137823,uid=0): Timeout waiting for handshake response
    Jul 15 10:08:16 box5 dovecot: imap-login: Error: conn unix:/run/dovecot/stats-writer (pid=4137823,uid=0): Timeout waiting for handshake response
    Jul 15 10:08:16 box5 dovecot: imap: Error: conn unix:/run/dovecot/stats-writer (pid=4137823,uid=0): Timeout waiting for handshake response
    Jul 15 10:08:16 box5 dovecot: managesieve: Error: conn unix:/run/dovecot/stats-writer (pid=4137823,uid=0): Timeout waiting for handshake response
    Jul 15 10:08:16 box5 dovecot: imap-login: Error: conn unix:/run/dovecot/stats-writer (pid=4137823,uid=0): Timeout waiting for handshake response
    Jul 15 10:08:16 box5 dovecot: message repeated 5 times: [ imap-login: Error: conn unix:/run/dovecot/stats-writer (pid=4137823,uid=0): Timeout waiting for handshake response]
    Jul 15 10:08:16 box5 dovecot: imap: Error: conn unix:/run/dovecot/stats-writer (pid=4137823,uid=0): Timeout waiting for handshake response
    Jul 15 10:08:16 box5 dovecot: message repeated 4 times: [ imap: Error: conn unix:/run/dovecot/stats-writer (pid=4137823,uid=0): Timeout waiting for handshake response]
    Jul 15 10:08:16 box5 dovecot: managesieve: Error: conn unix:/run/dovecot/stats-writer (pid=4137823,uid=0): Timeout waiting for handshake response
    Jul 15 10:08:16 box5 dovecot: message repeated 3 times: [ managesieve: Error: conn unix:/run/dovecot/stats-writer (pid=4137823,uid=0): Timeout waiting for handshake response]
    Jul 15 10:08:16 box5 dovecot: lmtp: Error: conn unix:/run/dovecot/stats-writer (pid=4137823,uid=0): Timeout waiting for handshake response
    Jul 15 10:08:16 box5 dovecot: lmtp: Error: conn unix:/run/dovecot/stats-writer (pid=4137823,uid=0): Timeout waiting for handshake response
    Jul 15 10:08:16 box5 dovecot: imap-login: Error: conn unix:/run/dovecot/stats-writer (pid=4137823,uid=0): Timeout waiting for handshake response
    Jul 15 10:08:16 box5 dovecot: lmtp: Error: conn unix:/run/dovecot/stats-writer (pid=4137823,uid=0): Timeout waiting for handshake response
    Jul 15 10:08:16 box5 dovecot: imap: Error: conn unix:/run/dovecot/stats-writer (pid=4137823,uid=0): Timeout waiting for handshake response
    Jul 15 10:08:16 box5 dovecot: managesieve: Error: conn unix:/run/dovecot/stats-writer (pid=4137823,uid=0): Timeout waiting for handshake response
    Jul 15 10:08:16 box5 dovecot: pop3: Error: conn unix:/run/dovecot/stats-writer (pid=4137823,uid=0): Timeout waiting for handshake response
    Jul 15 10:08:16 box5 dovecot: imap: Error: conn unix:/run/dovecot/stats-writer (pid=4137823,uid=0): Timeout waiting for handshake response
    Jul 15 10:08:16 box5 dovecot: lmtp: Error: conn unix:/run/dovecot/stats-writer (pid=4137823,uid=0): Timeout waiting for handshake response
    Jul 15 10:08:16 box5 dovecot: message repeated 2 times: [ lmtp: Error: conn unix:/run/dovecot/stats-writer (pid=4137823,uid=0): Timeout waiting for handshake response]
    Jul 15 10:08:16 box5 dovecot: pop3: Error: conn unix:/run/dovecot/stats-writer (pid=4137823,uid=0): Timeout waiting for handshake response
    Jul 15 10:08:16 box5 dovecot: message repeated 6 times: [ pop3: Error: conn unix:/run/dovecot/stats-writer (pid=4137823,uid=0): Timeout waiting for handshake response]
    Jul 15 10:08:16 box5 dovecot: managesieve: Error: conn unix:/run/dovecot/stats-writer (pid=4137823,uid=0): Timeout waiting for handshake response
    Jul 15 10:08:16 box5 dovecot: managesieve: Error: conn unix:/run/dovecot/stats-writer (pid=4137823,uid=0): Timeout waiting for handshake response
    Jul 15 10:08:16 box5 dovecot: lmtp: Error: conn unix:/run/dovecot/stats-writer (pid=4137823,uid=0): Timeout waiting for handshake response
    Jul 15 10:08:16 box5 dovecot: message repeated 2 times: [ lmtp: Error: conn unix:/run/dovecot/stats-writer (pid=4137823,uid=0): Timeout waiting for handshake response]
    Jul 15 10:08:16 box5 dovecot: pop3: Error: conn unix:/run/dovecot/stats-writer (pid=4137823,uid=0): Timeout waiting for handshake response
    Jul 15 10:08:16 box5 dovecot: pop3-login: Error: conn unix:/run/dovecot/stats-writer (pid=4137823,uid=0): Timeout waiting for handshake response


All stats configuration is as default seeing by dovecot -a

service stats {
  chroot =
  client_limit = 0
  drop_priv_before_exec = no
  executable = stats
  extra_groups =
  group =
  idle_kill = 4294967295 secs
  privileged_group =
  process_limit = 1
  process_min_avail = 0
  protocol =
  service_count = 0
  type =
  unix_listener stats-reader {
    group =
    mode = 0600
    user =
  }
  unix_listener stats-writer {
    group = $default_internal_group
    mode = 0660
    user =
  }
  user = $default_internal_user
  vsz_limit = 18446744073709551615 B
}

I don't use this dovecot stats service and I don't have metrics configured. Actually I wanted to know if it is possible to deactivate it because we do not use it here in the company.

Do you have anything else in the logs? Did you increase client_limit for stats service?