DHCP hostname auto add to unbound DNS silently fails

[sqrtofminus1]

Yesterday was the second time in 30 days, the auto add of DHCP hostname to unbound DNS failed silently.
I use virt-install with interfaces configured as dhcp - Normally, opnsense adds the name and assigned IP address in unbound DNS -however it started failing yesterday. I tried adding DHCP_HOSTNAME or DHCP_FQDN in the ifcfg-eth0 file, but still no entry in unbound DNS.

The solution, I found was to uncheck the "Register ISC DHCP4 leases" and "Register DHCP Static mappings" in Unbound DNS->General and then apply. Wait for 5 seconds and check again and apply.

This solves my problem.

If someone is interested in reviewing the issue - what all information is need to upload?

Thanks.