After system reboot Hitch binds only to TCP v6

[Benik3]

Hello.
I'm trying Hitch on SBC Unipi G100 using Debian 10 and Hitch 1.8.0 (compiled from master) for terminating http server (old one written in C).
I have the Hitch working, except that when I restart the SBC, Hitch binds only to TCP v6, not to v4. After manual restart of service it binds OK. In logs there are no errors.
Any idea?

/etc/hitch/hitch.conf

frontend = "[*]:443"
daemon = on
backend = "[127.0.0.1]:80"
pem-dir = "/etc/hitch/cert.d"
alpn-protos = "http/1.1"
user = unipi
syslog = on
log-level=2

/etc/systemd/system/hitch.service

[Unit]
Description=hitch
After=syslog.target network.target

[Service]
Type=forking
User=root
Group=root
Restart=on-failure
LimitNOFILE=131072
Environment="HITCH_OPTIONS=--config /etc/hitch/hitch.conf"
EnvironmentFile=-/etc/hitch/hitch.params
EnvironmentFile=-/etc/default/hitch
EnvironmentFile=-/etc/sysconfig/hitch
ExecStartPre=/usr/local/sbin/hitch -t $HITCH_OPTIONS
ExecStart=/usr/local/sbin/hitch --daemon $HITCH_OPTIONS
ExecReload=/bin/kill -HUP $MAINPID

[Install]
WantedBy=multi-user.target

journalctl -u hitch

Oct 02 10:47:19 G100-sn1112 systemd[1]: Starting hitch...
Oct 02 10:47:19 G100-sn1112 hitch[281]: Trying to initialize SSL contexts with your certificates
Oct 02 10:47:20 G100-sn1112 hitch[281]: {core} Note: no DH parameters found in /etc/hitch/cert.d/xxx.pem
Oct 02 10:47:20 G100-sn1112 hitch[281]: 20231002T104720.041502 [  281] {core} Note: no DH parameters found in /etc/hitch/cert.d/xxx.pem
Oct 02 10:47:20 G100-sn1112 hitch[281]: 20231002T104720.041952 [  281] {core} ECDH Initialized
Oct 02 10:47:20 G100-sn1112 hitch[281]: {core} ECDH Initialized
Oct 02 10:47:20 G100-sn1112 hitch[281]: hitch configuration looks ok.
Oct 02 10:47:20 G100-sn1112 hitch[289]: {core} hitch 1.8.0 starting
Oct 02 10:47:20 G100-sn1112 hitch[289]: {core} Using OpenSSL version 101010ef.
Oct 02 10:47:20 G100-sn1112 hitch[289]: 20231002T104720.117279 [  289] {core} hitch 1.8.0 starting
Oct 02 10:47:20 G100-sn1112 hitch[289]: 20231002T104720.117565 [  289] {core} Using OpenSSL version 101010ef.
Oct 02 10:47:20 G100-sn1112 hitch[289]: {core} Loading certificate pem files (1)
Oct 02 10:47:20 G100-sn1112 hitch[289]: 20231002T104720.139957 [  289] {core} Loading certificate pem files (1)
Oct 02 10:47:20 G100-sn1112 hitch[289]: {core} Note: no DH parameters found in /etc/hitch/cert.d/xxx.pem
Oct 02 10:47:20 G100-sn1112 hitch[289]: {core} ECDH Initialized
Oct 02 10:47:20 G100-sn1112 hitch[289]: 20231002T104720.145489 [  289] {core} Note: no DH parameters found in /etc/hitch/cert.d/xxx.pem
Oct 02 10:47:20 G100-sn1112 hitch[289]: 20231002T104720.145605 [  289] {core} ECDH Initialized
Oct 02 10:47:20 G100-sn1112 hitch[294]: {core} Listening on [::]:443
Oct 02 10:47:20 G100-sn1112 hitch[294]: {core} Process 0 online
Oct 02 10:47:20 G100-sn1112 hitch[293]: {core} hitch 1.8.0 initialization complete
Oct 02 10:47:20 G100-sn1112 systemd[1]: Started hitch.
Oct 02 10:47:20 G100-sn1112 hitch[294]: {core} Successfully attached to CPU #0
Oct 02 10:47:20 G100-sn1112 hitch[295]: {ocsp} Note: No OCSP responder URI found for cert /etc/hitch/cert.d/xxx.pem

netstat

After manual service restart