@0juke If you did not make any changes to your dhcp server then that is the primary problem. PXE booting client relies on 2 settings in dhcp. They are dhcp option 66 {next-server} and dhcp option 67 {boot-file}. These options tell the pxe booting client how to boot.
For dhcp option 66 that needs to be the IP address of the fog server.
For dhcp option 67 needs to be undionly.kpxe for bios based computers and ipxe.efi for uefi based computers.
Without these settings the client computer will not know how to boot.