Both traefik containers (on the “server” and “client” VMs) and the wireguard server container were built with TRAEFIK_NETWORK_MODE=host. The VMs can ping each other and the Wireguard containers can ping each other.
Both traefik containers were built with TRAEFIK_LOG_LEVEL=warn but I changed them both to TRAEFIK_LOG_LEVEL=info just now. There’s a tad more info in the logs, but nothing that seems pertinent.