Why 3 DKIM signatures?

Question

postfix

Good day to all.
I noticed that my letters are signed with three signatures, which is not good. I can't figure out how to leave just one.
opendkim.conf

AutoRestart             Yes
AutoRestartRate         10/1h
Umask                   002
Syslog                  yes
SyslogSuccess           Yes
LogWhy                  Yes
Canonicalization        relaxed/simple
ExternalIgnoreList      refile:/etc/opendkim/TrustedHosts
InternalHosts           refile:/etc/opendkim/TrustedHosts
KeyTable                refile:/etc/opendkim/KeyTable
SigningTable            refile:/etc/opendkim/SigningTable
Mode                    sv
PidFile                 /var/run/opendkim/opendkim.pid
SignatureAlgorithm      rsa-sha256
UserID                  opendkim:opendkim
Socket                  inet:[email protected]

postfix master.cf

smtp      inet  n       -       n       -       -       smtpd
    -o content_filter=spamassassin
    

submission     inet  n       -       n       -       -       smtpd
    -o content_filter=spamassassin
    -o smtpd_tls_security_level=may
    -o smtpd_sasl_auth_enable=yes
    -o smtpd_sasl_type=dovecot
    -o smtpd_sasl_path=/var/spool/postfix/private/auth
    -o smtpd_sasl_security_options=noanonymous
    -o smtpd_sasl_local_domain=$myhostname

smtps      inet n - n - - smtpd
    -o syslog_name=postfix/smtps
    -o smtpd_tls_wrappermode=yes
    -o smtpd_sasl_auth_enable=yes
    -o smtpd_client_restrictions=permit_sasl_authenticated,reject

dovecot    unix  -       n       n       -        -       pipe
    flags=DRhu user=vmail:vmail argv=/usr/libexec/dovecot/deliver -d ${recipient}

scan unix - - n - 16 smtp
     -o smtp_send_xforward_command=yes
     -o smtp_enforce_tls=no

127.0.0.1:10026 inet n - n - 16 smtpd
      -o content_filter=
      -o receive_override_options=no_unknown_recipient_checks,no_header_body_checks
      -o smtpd_helo_restrictions=
      -o smtpd_client_restrictions=
      -o smtpd_sender_restrictions=
      -o smtpd_recipient_restrictions=permit_mynetworks,reject
      -o mynetworks_style=host
      -o smtpd_authorized_xforward_hosts=127.0.0.0/8

spamassassin      unix  -       n       n       -       -       pipe
            flags=R user=spamd argv=/usr/bin/spamc -u spamd -e /usr/sbin/sendmail -oi -f $sender $recipient

postfix main.cf

smtpd_milters = inet:127.0.0.1:8891
receive_override_options = no_address_mappings
non_smtpd_milters = $smtpd_milters
milter_default_action = accept
milter_protocol = 2
content_filter = scan:[127.0.0.1]:10025

transport_maps = hash:/etc/postfix/transport_maps

Answer 1

Try temporarily commenting out these lines:

submission     inet  n       -       n       -       -       smtpd
    -o content_filter=spamassassin
    -o smtpd_tls_security_level=may
    -o smtpd_sasl_auth_enable=yes
    -o smtpd_sasl_type=dovecot
    -o smtpd_sasl_path=/var/spool/postfix/private/auth
    -o smtpd_sasl_security_options=noanonymous
    -o smtpd_sasl_local_domain=$myhostname

smtps      inet n - n - - smtpd
    -o syslog_name=postfix/smtps
    -o smtpd_tls_wrappermode=yes
    -o smtpd_sasl_auth_enable=yes
    -o smtpd_client_restrictions=permit_sasl_authenticated,reject

Although this is unlikely to help, only the ports will fall off - for some reason it runs through the miller 3 times, perhaps the antivirus returns to smtpd again, but it seems that it is not visible in the configs.
Upd,
Looks like an antivirus, yes, correct it like this:
===
127.0.0.1:10026 inet n - n - 16 smtpd
-o content_filter=
-o receive_override_options=no_unknown_recipient_checks,no_header_body_checks ,no_milters
===
What would he not apply when returning to smtpd Milters.