You could do a packet capture on the bridge and member interfaces and look at:- Do arp requests and arp replies work correctly?- Do the packets move from interface, to bridge, and out of the other interface?- Do Firewall rules block your packets?
Post the complete output of "ifconfig" on your OPNsense, please.
igb0: flags=8943<UP,BROADCAST,RUNNING,PROMISC,SIMPLEX,MULTICAST> metric 0 mtu 1500 description: NIC_Port_1 (opt3) options=4800028<VLAN_MTU,JUMBO_MTU,HWSTATS,MEXTPG> ether 00:1b:21:41:5c:10 inet6 fe80::21b:21ff:fe41:5c10%igb0 prefixlen 64 scopeid 0x1 media: Ethernet autoselect status: no carrier nd6 options=21<PERFORMNUD,AUTO_LINKLOCAL>igb1: flags=8943<UP,BROADCAST,RUNNING,PROMISC,SIMPLEX,MULTICAST> metric 0 mtu 1500 description: NIC_Port_2 (opt1) options=4800028<VLAN_MTU,JUMBO_MTU,HWSTATS,MEXTPG> ether 00:1b:21:41:5c:11 inet6 fe80::21b:21ff:fe41:5c11%igb1 prefixlen 64 scopeid 0x2 media: Ethernet autoselect status: no carrier nd6 options=21<PERFORMNUD,AUTO_LINKLOCAL>igb2: flags=8943<UP,BROADCAST,RUNNING,PROMISC,SIMPLEX,MULTICAST> metric 0 mtu 1500 description: NIC_Port_3 (opt2) options=4800028<VLAN_MTU,JUMBO_MTU,HWSTATS,MEXTPG> ether 00:1b:21:41:5c:14 inet6 fe80::21b:21ff:fe41:5c14%igb2 prefixlen 64 scopeid 0x3 media: Ethernet autoselect status: no carrier nd6 options=21<PERFORMNUD,AUTO_LINKLOCAL>igb3: flags=1008943<UP,BROADCAST,RUNNING,PROMISC,SIMPLEX,MULTICAST,LOWER_UP> metric 0 mtu 1500 description: NIC_Port_4 (opt5) options=4800028<VLAN_MTU,JUMBO_MTU,HWSTATS,MEXTPG> ether 00:1b:21:41:5c:15 inet6 fe80::21b:21ff:fe41:5c15%igb3 prefixlen 64 scopeid 0x4 media: Ethernet autoselect (1000baseT <full-duplex>) status: active nd6 options=21<PERFORMNUD,AUTO_LINKLOCAL>em0: flags=1008843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST,LOWER_UP> metric 0 mtu 1500 description: Modem_DSL (opt6) options=4802028<VLAN_MTU,JUMBO_MTU,WOL_MAGIC,HWSTATS,MEXTPG> ether 4c:cc:6a:b3:d0:39 inet 192.168.178.21 netmask 0xffffff00 broadcast 192.168.178.255 inet6 fe80::4ecc:6aff:feb3:d039%em0 prefixlen 64 scopeid 0x5 media: Ethernet autoselect (1000baseT <full-duplex>) status: active nd6 options=21<PERFORMNUD,AUTO_LINKLOCAL>lo0: flags=1008049<UP,LOOPBACK,RUNNING,MULTICAST,LOWER_UP> metric 0 mtu 16384 options=680003<RXCSUM,TXCSUM,LINKSTATE,RXCSUM_IPV6,TXCSUM_IPV6> inet 127.0.0.1 netmask 0xff000000 inet6 ::1 prefixlen 128 inet6 fe80::1%lo0 prefixlen 64 scopeid 0x6 groups: lo nd6 options=21<PERFORMNUD,AUTO_LINKLOCAL>enc0: flags=0 metric 0 mtu 1536 options=0 groups: enc nd6 options=23<PERFORMNUD,ACCEPT_RTADV,AUTO_LINKLOCAL>pfsync0: flags=0 metric 0 mtu 1500 options=0 maxupd: 128 defer: off version: 1400 syncok: 1 groups: pfsyncpflog0: flags=20100<PROMISC,PPROMISC> metric 0 mtu 33152 options=0 groups: pflogwg0: flags=10080c1<UP,RUNNING,NOARP,MULTICAST,LOWER_UP> metric 0 mtu 1420 description: HomeWireGuard (opt7) options=80000<LINKSTATE> inet 10.10.10.1 netmask 0xffffff00 groups: wg wireguard nd6 options=1<PERFORMNUD>bridge0: flags=1008843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST,LOWER_UP> metric 0 mtu 1500 description: LAN (lan) options=0 ether 58:9c:fc:10:ff:a0 inet 10.0.0.1 netmask 0xffffff00 broadcast 10.0.0.255 inet 10.10.1.1 netmask 0xffffff00 broadcast 10.10.1.255 inet 10.0.1.1 netmask 0xffffff00 broadcast 10.0.1.255 id 00:00:00:00:00:00 priority 32768 hellotime 2 fwddelay 15 maxage 20 holdcnt 6 proto rstp maxaddr 2000 timeout 1200 root id 00:00:00:00:00:00 priority 32768 ifcost 0 port 0 member: igb3 flags=143<LEARNING,DISCOVER,AUTOEDGE,AUTOPTP> ifmaxaddr 0 port 4 priority 128 path cost 20000 member: igb2 flags=143<LEARNING,DISCOVER,AUTOEDGE,AUTOPTP> ifmaxaddr 0 port 3 priority 128 path cost 2000000 member: igb1 flags=143<LEARNING,DISCOVER,AUTOEDGE,AUTOPTP> ifmaxaddr 0 port 2 priority 128 path cost 2000000 member: igb0 flags=143<LEARNING,DISCOVER,AUTOEDGE,AUTOPTP> ifmaxaddr 0 port 1 priority 128 path cost 2000000 groups: bridge nd6 options=9<PERFORMNUD,IFDISABLED>pppoe0: flags=10088d1<UP,POINTOPOINT,RUNNING,NOARP,SIMPLEX,MULTICAST,LOWER_UP> metric 0 mtu 1492 description: WAN (wan) options=0 inet 93.130.155.253 --> 62.52.193.57 netmask 0xffffffff inet6 fe80::21b:21ff:fe41:5c10%pppoe0 prefixlen 64 scopeid 0xb nd6 options=21<PERFORMNUD,AUTO_LINKLOCAL>ue0: flags=1008843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST,LOWER_UP> metric 0 mtu 1500 description: WAN_LTE (opt4) options=80000<LINKSTATE> ether 00:1e:10:1f:00:00 inet 192.168.8.10 netmask 0xffffff00 broadcast 192.168.8.255 inet6 fe80::21e:10ff:fe1f:0%ue0 prefixlen 64 scopeid 0xa media: Ethernet autoselect status: active nd6 options=21<PERFORMNUD,AUTO_LINKLOCAL>
So your bridge has got four member interfaces - igb0-3 and the configuration looks good.I assume em0 is your WAN interface with pppoe0 running on top of that.From your output only one of the four bridged ports has got any connection. All others have "no carrier". If that is intentional because you are running everything via your switch - ok. If there is a system connected to one of the "no carrier" ports, check the cabling.If the tunables are in place and the "LAN" or whatever you name it interface is assigned to the bridge, everything looks good.If you can answer all implicit question with "yes, of course, by the docs" - the next step in my book would be packet traces to watch what is actually happening on the wire.HTH,Patrick