Config error is REFUSED every night

With pleasure:

pihole-FTL dhcp-discover
Scanning all your interfaces for DHCP servers
Timeout: 10 seconds

* Received 329 bytes from eth0:192.168.1.4
  Offered IP address: 192.168.1.179
  Server IP address: 192.168.1.20
  Relay-agent IP address: N/A
  BOOTP server: (empty)
  BOOTP file: netboot.xyz.kpxe
  DHCP options:
   Message type: DHCPOFFER (2)
   server-identifier: 192.168.1.4
   lease-time: 86400 ( 1d )
   renewal-time: 43200 ( 12h )
   rebinding-time: 75600 ( 21h )
   netmask: 255.255.255.0
   broadcast: 192.168.1.255
   dns-server: 192.168.1.4
   domain-name: "highpeak.co.za"
   tftp-server: "192.168.1.20\0"
   ntp-server: 192.168.1.4
   router: 192.168.1.1
   --- end of options ---

DHCP packets received on interface eth0: 1
DHCP packets received on interface wlan0: 0
DHCP packets received on interface lo: 0

I have the following files:


-rw-r--r--  1 root root 1495 May 30 19:43 01-pihole.conf
-rw-r--r--  1 root root  670 May 30 19:43 02-pihole-dhcp.conf
-rw-r--r--  1 root root 4013 May  2 14:36 04-pihole-static-dhcp.conf
-rw-r--r--  1 root root  489 Nov 17  2020 99-pihole-custom.conf

BTW - no issues last night after switching to Cloudflare DNS instead of OpenDNS