25.1.6_2 and 25.1.6_4 problem with Kea DHCPv4/DHCPv6 dual operation

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I have have two VLANs configured to seperate work traffic (myself and daughter) from home traffic. Currently I did have ISC DHCPv4 and DHCPv6 configured to supply both IPv4 and IPv6 traffic to work devices. After upgrading to 25.1.6_2 I performed a backup and then disabled ISC DHCPv4 and DHCPv6 and configured the same networks onto Kea DHCPv4 and DHCPv6. Initially with 25.1.6_2 I did managed to get an IPv4 and IPv6 address on my laptop but the lease did not appear. However after a power cycle the my laptop obtained an IPv4 and IPv6 address with both the IPv4 and IPv6 lease appearing; my daughter's laptop never obtained an IP address.
After upgrading to 25.1.6_4 I am able to obtain an IPv6 address but unable to obtain an IPv4 address, reverting to using ISC DHCP by restoring a backup IP addresses are always obtained.
If I power cycle 25.1.6_4 using the Kea backup, then my laptop does get IPv6 address immediately and then will get an IPv4 address, however only the IPv6 lease appears in Leases DHCPv6, nothing appears in Leases DHCPv4. If I restart the Kea DHCP service then I stop getting an IPv4 address and only obtain an IPv6 address

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After checking the KEA Logs (informational) with 25.1.6_4, after a power cycle the logs show my laptop communicating with KEA and obtaining an IPv6 address then after a brief period it shows the laptop going through the DORA process and obtaining IPv4 address. After restarting the KEA Service and power cycling the laptop, the logs show an IPv6 address SARR process, however the IPv4 only completes DO or DORA, an DHCPOFFER is sent but there is never any response.
In respect of my daughter's connection, I connected a laptop to her network connection and could not get an IPv6 or IPv4 address checking the logs it shows that for IPv6 it completes SA of SARR and DO or DORA. In both cases I am using automated firewall rules, checking them manually they appear to be correct.
Both VLANs are connected to LAG interface connecting the 25.1.6_4 to my switch.
Restoring the ISC DHCP backup and with the attendant reboot, everything works as normal. So it is not a network issue, it appears to be directly related to ISC Kea.