That works for me too :-)

Apr 27 18:43:50 mephi-server systemd-networkd[799]: br107: netdev ready
Apr 27 18:43:50 mephi-server systemd-networkd[799]: br1: netdev ready
Apr 27 18:43:50 mephi-server systemd-networkd[799]: br0: netdev ready
Apr 27 18:43:50 mephi-server systemd-networkd[799]: Enumeration completed
Apr 27 18:43:50 mephi-server systemd-networkd[799]: br107: IPv6 successfully enabled
Apr 27 18:43:50 mephi-server systemd-networkd[799]: br1: IPv6 successfully enabled
Apr 27 18:43:50 mephi-server systemd-networkd[799]: br0: IPv6 successfully enabled
Apr 27 18:43:50 mephi-server systemd-networkd-wait-online[982]: managing: br1
Apr 27 18:43:50 mephi-server systemd-networkd-wait-online[982]: managing: br1
Apr 27 18:43:50 mephi-server systemd-networkd-wait-online[982]: managing: br1
Apr 27 18:43:50 mephi-server systemd-networkd-wait-online[982]: managing: br1
Apr 27 18:43:50 mephi-server systemd-networkd[799]: br107: Link UP
Apr 27 18:43:50 mephi-server systemd-networkd[799]: br107: Gained carrier
Apr 27 18:43:50 mephi-server systemd-networkd[799]: br1: Link UP
Apr 27 18:43:50 mephi-server systemd-networkd[799]: br1: Gained carrier
Apr 27 18:43:50 mephi-server systemd-networkd-wait-online[982]: managing: br1
Apr 27 18:43:50 mephi-server systemd-networkd[799]: br0: Link UP
Apr 27 18:43:50 mephi-server systemd-networkd[799]: br0: Gained carrier
Apr 27 18:43:50 mephi-server systemd-networkd[799]: br0: Lost carrier
Apr 27 18:43:50 mephi-server systemd-networkd[799]: vlan107: netdev ready
Apr 27 18:43:50 mephi-server systemd-networkd[799]: enp4s0f3: Link UP
Apr 27 18:43:50 mephi-server systemd-networkd[799]: vlan107: Link UP
Apr 27 18:43:50 mephi-server systemd-networkd[799]: br107: Lost carrier
Apr 27 18:43:50 mephi-server systemd-networkd[799]: br0: Gained IPv6LL
Apr 27 18:43:50 mephi-server systemd-networkd[799]: br107: Gained IPv6LL
Apr 27 18:43:50 mephi-server systemd-networkd[799]: br1: Gained IPv6LL
Apr 27 18:43:50 mephi-server systemd-networkd-wait-online[982]: managing: br1
Apr 27 18:43:50 mephi-server systemd-networkd-wait-online[982]: managing: br0
Apr 27 18:43:50 mephi-server systemd-networkd-wait-online[982]: managing: vlan107
Apr 27 18:43:50 mephi-server systemd-networkd-wait-online[982]: managing: br107
Apr 27 18:43:50 mephi-server systemd[1]: Starting Dispatcher daemon for systemd-networkd...
Apr 27 18:43:50 mephi-server networkd-dispatcher[1136]: No valid path found for iwconfig
Apr 27 18:43:50 mephi-server systemd[1]: Started Dispatcher daemon for systemd-networkd.
Apr 27 18:43:51 mephi-server systemd-networkd-wait-online[982]: managing: br1
Apr 27 18:43:51 mephi-server systemd-networkd[799]: enp4s0f3: Gained carrier
Apr 27 18:43:51 mephi-server systemd-networkd-wait-online[982]: managing: br0
Apr 27 18:43:51 mephi-server systemd-networkd-wait-online[982]: managing: vlan107
Apr 27 18:43:51 mephi-server systemd-networkd-wait-online[982]: managing: br107
Apr 27 18:43:51 mephi-server systemd-networkd-wait-online[982]: managing: br1
Apr 27 18:43:51 mephi-server systemd-networkd-wait-online[982]: managing: br0
Apr 27 18:43:51 mephi-server systemd-networkd-wait-online[982]: managing: vlan107
Apr 27 18:43:51 mephi-server systemd-networkd-wait-online[982]: managing: br107
Apr 27 18:43:51 mephi-server systemd-networkd-wait-online[982]: managing: br1
Apr 27 18:43:51 mephi-server systemd-networkd-wait-online[982]: managing: br0
Apr 27 18:43:51 mephi-server systemd-networkd-wait-online[982]: managing: vlan107
Apr 27 18:43:51 mephi-server systemd-networkd-wait-online[982]: managing: br107
Apr 27 18:43:51 mephi-server systemd-networkd-wait-online[982]: managing: br1
Apr 27 18:43:51 mephi-server systemd-networkd-wait-online[982]: managing: br0
Apr 27 18:43:51 mephi-server systemd-networkd-wait-online[982]: managing: vlan107
Apr 27 18:43:51 mephi-server systemd-networkd-wait-online[982]: managing: br107
Apr 27 18:43:51 mephi-server systemd-networkd[799]: br0: Gained carrier
Apr 27 18:43:51 mephi-server systemd-networkd-wait-online[982]: managing: br1
Apr 27 18:43:51 mephi-server systemd-networkd-wait-online[982]: managing: br0
Apr 27 18:43:51 mephi-server systemd-networkd-wait-online[982]: managing: vlan107
Apr 27 18:43:51 mephi-server systemd-networkd-wait-online[982]: managing: br107
Apr 27 18:43:51 mephi-server systemd-networkd[799]: vlan107: Gained carrier
Apr 27 18:43:51 mephi-server systemd-networkd-wait-online[982]: managing: br1
Apr 27 18:43:51 mephi-server systemd-networkd-wait-online[982]: managing: br0
Apr 27 18:43:51 mephi-server systemd-networkd-wait-online[982]: managing: vlan107
Apr 27 18:43:51 mephi-server systemd-networkd-wait-online[982]: managing: br107
Apr 27 18:43:51 mephi-server systemd-networkd-wait-online[982]: managing: enp4s0f3
Apr 27 18:43:51 mephi-server systemd-networkd[799]: br107: Gained carrier
Apr 27 18:43:57 mephi-server networkd-dispatcher[1136]: WARNING:Unknown index 10 seen, reloading interface list
Apr 27 18:43:57 mephi-server systemd-networkd[799]: veth0ce1af8f: Link UP
Apr 27 18:43:57 mephi-server systemd-networkd[799]: veth0ce1af8f: Gained carrier