Traffic monitor problem

problem: openwrt doesn't catch packets between lan ports.

Model: YouHua WR1200JS
Architecture: MediaTek MT7621 ver:1 eco:3
Target Platform: ramips/mt7621
Firmware Version: OpenWrt 22.03.5 r20134-5f15225c1e / LuCI openwrt-22.03 branch git-23.093.57104-ce20b4a

network topology:

PS: iftop -nNp -i lan4
PS: is a network camera.

As all devices are on the same network, I assume they are not acting as routers, but switches or access points. In that case, the traffic does not reach the CPU, it traverses the device through the embedded switch.

You can configure the devices as routers, separate the LAN ports using VLANs, create mirror ports, etc.