OpenWRT: WireGuard with PBR and IPv6

[Whisperer 2]

I am trying to set up my new OpenWRT router with WireGuard and PBR while keeping IPv6 enabled.

I found previous threads and followed some of the instructions found there, namely the ones on this page:
https://openwrt.org/docs/guide-user/services/vpn/wireguard/client
and this video by Dev Odyssey:
https://www.youtube.com/watch?v=04q41GEPvKA

The deviation from the above I made is to add the DNS servers, which are not in the OpenWRT page. I also created a "vpn" zone and added it to the default forwarder as in the video.

I installed PBR and started it with IPv6 enabled.

The WireGuard connection appears to be online. However, even though DNS resolution appears to work, I have no IPv4 connectivity and can only connect to IPv6 sites with my ISP's IPv6 address. So basically even though the WireGuard connection is established and has a small amount of TX and RX I don't appear to be able to use the tunnel at all (except for DNS resolution so I can reach AirVPN's DNS).

I'm at a loss how to troubleshoot this. Anybody able to assist?