As a quick & dirty workaround put this in autostart.sh
ip link set dev eth0 address 00:A2:3F:12:0A:10
systemctl restart connman
and mac will stay always the same (you can use different mac). And you can set static ip address in settings.
Or something like that (probably nicer)
cat > /storage/.config/system.d/set-mac-address.service <<EOF
[Unit]
Description=Set MAC address
Before=network.target
Wants=network.target
[Service]
Type=oneshot
ExecStart=/usr/sbin/ip link set dev eth0 address 00:A2:3F:12:0A:10
RemainAfterExit=yes
[Install]
WantedBy=multi-user.target
EOF
systemctl enable set-mac-address
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