Device in ARP - using the network address?

I've never seen this before, so I just want a sanity check as to how this is showing up in ARP - on my cisco L3 switch there appears to be a misconfigured device, as it shows up in arp on the network address.

We have two networks, 192.168.1.0/25, & 192.168.1.128/27 defined as vlans on the cisco.

There is a device showing up on the 192.168.1.128 in ARP.

Clearly there is a device with the wrong subnet configured, I'm just confused as to how the switch is even putting this in arp, as it's the network address for the 192.168.1.128/27 network that is defined on that switch.