Router replying to requests on SUBNET address

Why does RouterOS reply to packets destined for the subnet or broadcast address (first and last address in subnet)? This just started in newer releases - but I do not know which one. I believe 6.19 did not have this problem.

RouterOS box has 192.168.1.1/24 on it. From another machine you can snmpwalk 192.168.1.0 (subnet address) or 192.168.1.255 (broadcast address) and the RouterOS router will respond to them as if they were sent to it. The response comes from a valid ip on the router.

This is causing Dude to discover the subnet address on hundreds of my subnets and generate phantom devices on the map.

Sam