Wild speculation:The IP is currently assigned to some router in a nearby carrier network that has decent connectivity to everything. Potentially the mobile carrier.
The OP happens to be connected to wifi at the DC. Tests across the mobile carrier network didnt take place thanks to route preference over wifi.
Something in carrier land is responding to the IP. It might be assigned in a stupid fashion, like every PE router is responding to it. Or anycast or something.
The OP has the ip address assigned to his laptop and phone. His own devices are responding to the pings.
OP might be using a different ping client that he isnt used to, and is taking 40ms as .4 ms. He doesn't really give us the measurement, just the value.
OP might be using a VPN and the VPN gateway router is responding to this ip with pings for whatever reason. Or the VPN client software has assigned this ip to his laptop.