Home assistant startup hangs when embedded mqtt broker and listener ports are different

Configuration
1

I have this setup in my configuration.yaml:

mqtt:
  embedded:
    listeners:
      default:
        max-connections: 500
        type: tcp
        bind: 127.0.0.1:1883
        user: mqttuser
  broker: 127.0.0.1
  port: 1883

This works now or at least it gives no errors. I actually do not know if its working… Previously I had the broker port set to 1888. HASS 0.38.1 stopped to boot up and did print nothing to syslog expect of:

Feb 12 23:18:37 homeautomation hass[538]: Config directory: /home/pi/.homeassistant

No further information about the error was given.