Also try changing your AllowedIPs to 10.11.13.0/24
In fact I don’t need to access anything on 10.11.12.13.0/24 - that’s the peer to peer wireguard network. I want to be able to connect to any host on 10.11.12.0/24. Adding this network to AllowedIPs I’m now able to connect to .77 (which is my server) and to .1 (the router), but not on any other hosts in the house.
The other issue may be the ability of the host/server to reach the IP address of the pihole macvlan interface. Have a look at this page, it’s helped me out before -> adventurenotvacation.com/…/docker-macvlan-and-deb…