What am I doing wrong?

I am trying to configure IPV6 on my PFSense Router.

I appear to be getting my /56 subnet, and my LAN clients are getting addresses, as I get 10/10 at test-ipv6.com

But every time I reboot the router. When it comes back up, I have no IPV4 connectivity, only IPV6.

IPV4 only comes back up when I change any of my WAN gateway settings, i.e changing MTU from empty to 1500 and clicking apply causes the router to connect to IPV4. And then next time I reboot, the same thing happens and it comes right again after changing MTU from 1500 back to empty. I.e the Interfaces/Gateway module needs to be reloaded.

I have not found any configuration that works, other than disabling IPV6 on my WAN interface.

Here are my WAN interface settings.

And I have tried a number of different LAN configurations, but currently I have my RA set to Managed mode and my DHCPV6 server configured correctly AFAIK

LAN Interface Config (other LAN networks are the same)

DHCPV6 Config

Any ideas?