client unexpectedly closed TCP connection

[a14n]

After a weekend without traffic on a rabbitmq connection the first publication leads to the following message in rabbitmq logs:

=INFO REPORT==== 22-Mar-2019::08:04:05 ===
connection <0.580.0> (10.233.77.108:54878 -> 10.233.81.213:5672): user 'guest' authenticated and granted access to vhost '/'

=WARNING REPORT==== 25-Mar-2019::07:54:25 ===
closing AMQP connection <0.580.0> (10.233.77.108:54878 -> 10.233.81.213:5672, vhost: '/', user: 'guest'):
client unexpectedly closed TCP connection

I don't really know why this happens because my dart code doesn't display anything in its logs (and it doesn't crash) although I set a errorListener:

      rabbitmqClient = amqp.Client(
        settings: amqp.ConnectionSettings(
          host: config.rabbitmq.host,
          port: config.rabbitmq.port,
          virtualHost: config.rabbitmq.virtualHost,
          authProvider: amqp.PlainAuthenticator(
            config.rabbitmq.user,
            config.rabbitmq.password,
          ),
        ),
      )..errorListener((e) {
          _log.warning('rabbit client error: $e');
          if (e is amqp.FatalException) {
            _log.severe('shutting down because of $e');
            exit(1);
          }
        });