@SBrady Looking at your pcap, you have 3 servers responding to the bootp request from your target computer. It appears the real dhcp server is at the .181 address and the 2 proxyDHCP servers are at .44 and .45. Both of the proxyDHCP servers are overriding what your main dhcp server is telling the target computer for where to get the boot file from.
I can’t tell from the proxyDHCP response what type of computer it is. The response doesn’t look like a Microsoft SCCM or WDS response because it is so short. I would focus on what .44 and .45 are and why they are responding to the bootp request.
Edit: Looking a bit more into the pcap there is also a WDS server responding to the DHCP DISCOVER query at the .217 address. That makes a total of 4 dhcp (and proxy servers responding) overriding what the main dhcp server was sending for dhcp options 66 and 67.