It seems like bbb-fsesl-akka uses the public IP to connect to Freeswitch ESL and gets rejected with
mod_event_socket.c:2663 IP 77.145.44.15 Rejected by acl "loopback.custom"
This leads to an endless "Connecting to echo test" dialog, because Meteor waits for an VoiceCallStateEvtMsg event on redis which doesn't get emitted by bbb-fsesl-akka.