Help with ZTD and S5248F-ON

Greetings, I have been following the instructions posted here: https://www.dell.com/support/manuals/en-in/dell-emc-smartfabric-os10/smartfabric-os-user-guide-10-5-0/dell-emc-smartfabric-os10-zero-touch-deployment?guid=guid-95ca07a2-2bcb-4ea2-84ef-ef9d11a4fa0e&lang=en-us and when I try configure a S5248F-ON, the switch gets an IP address assigned but it never starts the ZTD part. Running a tcpdump on the server I can see the switch sending data but nothing related to ZTD or option 240. The only thing different from the guide is the DHCP server is running Kea since it's replacing ISC DHCP. Does anyone have any pointers or suggestions?

Thanks,

Freddy Rojas