When I look for DHCP problems using a | grep dhcp, I don't get anything. If I look at the eth0 interface here is what I get:
LibreELEC:~ # journalctl | grep eth0
Mar 24 16:12:13 LibreELEC kernel: smsc95xx 1-1.1:1.0 eth0: register 'smsc95xx' at usb-3f980000.usb-1.1, smsc95xx USB 2.0 Ethernet, b8:27:eb:04:35:27
Mar 24 16:12:14 LibreELEC systemd-udevd[275]: Process '/bin/sh -c 'echo enabled >/sys/class/net/eth0/device/power/wakeup' ' failed with exit code 1.
Mar 24 16:12:15 LibreELEC connmand[325]: eth0 {create} index 2 type 1 <ETHER>
Mar 24 16:12:15 LibreELEC connmand[325]: eth0 {update} flags 4098 <DOWN>
Mar 24 16:12:15 LibreELEC connmand[325]: eth0 {newlink} index 2 address B8:27:EB:04:35:27 mtu 1500
Mar 24 16:12:15 LibreELEC connmand[325]: eth0 {newlink} index 2 operstate 2 <DOWN>
Mar 24 16:12:15 LibreELEC connmand[325]: Adding interface eth0 [ ethernet ]
Mar 24 16:12:15 LibreELEC kernel: smsc95xx 1-1.1:1.0 eth0: hardware isn't capable of remote wakeup
Mar 24 16:12:15 LibreELEC kernel: IPv6: ADDRCONF(NETDEV_UP): eth0: link is not ready
Mar 24 16:12:15 LibreELEC connmand[325]: eth0 {update} flags 36867 <UP>
Mar 24 16:12:15 LibreELEC connmand[325]: eth0 {newlink} index 2 address B8:27:EB:04:35:27 mtu 1500
Mar 24 16:12:15 LibreELEC connmand[325]: eth0 {newlink} index 2 operstate 2 <DOWN>
Apr 24 22:48:50 LibreELEC connmand[325]: eth0 {add} route ff00:: gw :: scope 0 <UNIVERSE>
Apr 24 22:48:50 LibreELEC connmand[325]: eth0 {add} route fe80:: gw :: scope 0 <UNIVERSE>
Apr 24 22:48:50 LibreELEC kernel: IPv6: ADDRCONF(NETDEV_CHANGE): eth0: link becomes ready
Apr 24 22:48:50 LibreELEC connmand[325]: eth0 {update} flags 102467 <UP,RUNNING,LOWER_UP>
Apr 24 22:48:50 LibreELEC connmand[325]: eth0 {newlink} index 2 address B8:27:EB:04:35:27 mtu 1500
Apr 24 22:48:50 LibreELEC connmand[325]: eth0 {newlink} index 2 operstate 6 <UP>
Apr 24 22:48:50 LibreELEC kernel: smsc95xx 1-1.1:1.0 eth0: link up, 100Mbps, full-duplex, lpa 0xC5E1
Apr 24 22:48:52 LibreELEC avahi-daemon[373]: Joining mDNS multicast group on interface eth0.IPv6 with address fe80::ba27:ebff:fe04:3527.
Apr 24 22:48:52 LibreELEC avahi-daemon[373]: New relevant interface eth0.IPv6 for mDNS.
Apr 24 22:48:52 LibreELEC avahi-daemon[373]: Registering new address record for fe80::ba27:ebff:fe04:3527 on eth0.*.
Apr 24 22:49:30 LibreELEC avahi-daemon[373]: Joining mDNS multicast group on interface eth0.IPv4 with address 169.254.212.6.
Apr 24 22:49:30 LibreELEC avahi-daemon[373]: New relevant interface eth0.IPv4 for mDNS.
Apr 24 22:49:30 LibreELEC avahi-daemon[373]: Registering new address record for 169.254.212.6 on eth0.IPv4.
Apr 24 22:49:30 LibreELEC connmand[325]: eth0 {add} address 169.254.212.6/16 label eth0 family 2
Apr 24 22:49:30 LibreELEC connmand[325]: eth0 {add} route 169.254.0.0 gw 0.0.0.0 scope 253 <LINK>
I've added the complete logs in attachment. I really don't understand where the problem could come from. I have 0 information about DHCP and I don't have any commands to retry it. What are the systemd commands that control the emission of DHCP requests?