mesh-broker serves the amqps bus on 5671 (the control plane and every module's events) but the lavinmq module declared only 5672, so the firewall's forward chain — where the broker's published ports are matched — never opened 5671, and a consumer on another node could not reach the bus over the overlay. Part of issue 055. https://claude.ai/code/session_01D6qtiYU3P9jk3pnAXyAFyx