Unreadable symbols in winston log file

Question

I am using winton for logging, the docker containers are hosted on a AWS ec2 instance. But when I read the logs from the docker there are unreadable symbols surrounding the logs, from another thread it could be the colour setting. But I did not specify the colours, is there any other possibilities?

Here is what the log looks like:

logs with unreadable symbols

Here is how I create the winston logger:

WinstonModule.createLogger({
      transports: [
        new transports.Console({
          level: "debug",
          format: format.combine(
              format.timestamp(),
              format.json()
          ),
        })
      ],
    });