@jveronese the combination of subnet mask and IP address will say they are on the same subnet.
i.e. 192.168.1.0 with a subnet mask of 255.255.255.0 would say they are on the same subnet.
OK if they are on the same subnet, we can use fog to see if we can detect what is going wrong with dhcp.
Follow these instructions and then upload the pcap to a google drive. We’ll take a look at the capture and see what is going on with dhcp
https://forums.fogproject.org/topic/9673/when-dhcp-pxe-booting-process-goes-bad-and-you-have-no-clue