FreeBSD laptop not getting IPv6 configured with SLAAC

Hello,

I am trying to get my laptop to receive an IPv6 address using SLAAC on 
my local network. I suspect that the router provided by my ISP is doing 
something slightly wrong or I may just have configured it wrong.

I am running FreeBSD 14.0-RELEASE-p3.

The network interface looks like this when queried with ifconfig.

wlan0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500
     options=0
     ether 18:1d:ea:b1:f9:8b
     inet 192.168.0.129 netmask 0xffffff00 broadcast 192.168.0.255
     inet6 fe80::1a1d:eaff:feb1:f98b%wlan0 prefixlen 64 scopeid 0x2
     groups: wlan
     ssid ARRIS-8030 channel 6 (2437 MHz 11g) bssid e4:f7:5b:25:ff:da
     regdomain FCC country US authmode WPA2/802.11i privacy ON
     deftxkey UNDEF AES-CCM 2:128-bit txpower 30 bmiss 10 scanvalid 60
     protmode CTS wme roaming MANUAL
     parent interface: iwm0
     media: IEEE 802.11 Wireless Ethernet OFDM/54Mbps mode 11g
     status: associated
     nd6 options=23<PERFORMNUD,ACCEPT_RTADV,AUTO_LINKLOCAL>

I have attached my rc.conf and pf.conf files to this mail.

I have also attached a tcpdump showing router solicitations going out 
and router advertisements being received.

My pf.conf should be open enough for this to work but for completeness I 
have also tried with pf disabled with the same result.

When running Ubuntu on the same laptop or even in a Virtualbox VM with 
bridged networking, Ubuntu manages to configure IPv6 without problems. 
Likewise with a Windows VM.

I appreciate if anyone here can spot what goes wrong and suggest if I 
need to configure something differently or whether a code fix will be 
needed to support this network. I can try patches if necessary.

Thanks.

Best regards
Kristian