It seems that the plugging and unplugging of the lan port network cable cannot trigger the hot plug event

I tried to wake up the computer on the LAN from the WAN using WOL, but I was in trouble. After inserting and unplugging the lan cable, the arp table created by ip neigh change * lladdr * nud permanent dev br-lan seems to be invalid.
I found a script that seems to handle this problem, but this script doesn't seem to work on my router (MT7620).
I created test scripts in the /etc/hotplug.d/net/ and /etc/hotplug.d/iface/ directories, but it seems that plugging in the lan network cable does not trigger these two hot plug events.
I don't know if this is a fault.:sob:

This is the script:

I do not think that unplugging a device on the LAN port should be considered as bringing the interface down...

There seems to be no way to keep arp flags 6, and there are no suitable events for triggering overwrite arp flags.:thinking: