I spent some time on Foreman instance that was not working properly. There
were literarly no leases or DHCP records, we verified this via curl that
proxy was not returning anything, but New Host creation was always failing
with 409 conflict.
It turned out there were two dhcpd processes running and because record
reading is done by reading conf/lease files but updates are via omshell,
the "wrong" process was actually causing the conflicts.
Killing those helped to put things back in order