Removing Duplicate Ping (DUP!) Information from Router ?!

[tryllz]

Hi,

All the below is in a virtual environment.

I have a Windows Server VM which when pinged from any other device shows (DUP!). I tried to flush the ARP in the OPNSense VM, but this does not change anything.

The IP address is only assigned to 1 device, the duplicate issue comes from changing the MAC address.

Can I  know how to get rid of old MAC address informatgion from the routrer ?

Thank You