OPNsense does not response to ARP requests for static entries

[JasMan]

Hi folks,

I've configured a DHCPv4 lease with static ARP entry containing the broadcast mac address ff:ff:ff:ff:ff:ff. I'm using this IP to send WoL packets from other subnets to reach all clients in this subnet.

Worked well for years. But now, I've no idea since when exactly, OPNsense doesn't reply to queries for this IP address.

I did a packet capture and the ARP queries are arriving on the right interface. But I can't see any response. Only when the clients request the gateway address, which is the OPNsense interface, I can see the responses.
Any idea ?

EDIT: The ARP table of OPNsense contains the static ARP entry.