DHCP IP conflict on proxy, IP doesn't exist in dhcpd.leases

I’m using Foreman 1.23.1 with two DHCP proxies set as a failover. I can’t reprovision the same host due to error with IP conflict. This error shows up even when an entry in dhcpd.leases doesn’t exist. To avoid this error I have to remove DHCP entry from dhcpd.leases and then restart dhcpd.service

Create DHCP Settings for am2-testapi008.dc.egnyte.lan task failed with the following error: ERF12-6899 [ProxyAPI::ProxyException]: Unable to set DHCP entry ([RestClient::Conflict]: 409 Conflict) for proxy https://am2-foreman-proxy-dhcp01.domain:8443/dhcp

More details, more logs, IP and lease addresses (are they the same?). If you change PXE loader this can lead to such conflict, this has been fixed recently.