Can traceroute but cannot ping the device

I have a device which I will install on my network and in doing some preliminary tests, I traceroute the IP address that I will assign to this device and the result was that I can reach it. If I tried to ping this IP address, there is no reply. The network engineer maintaining the the LAN confirmed to me that he has not assigned the IP number that I will use to any device. Appreciate if you can tell me what is happening here!