[bug] Nest SSE not working

[ohmygodvt95]

Describe the bug
When I use Nest's SSE, it seems like the data part has disappeared.

To Reproduce
In the controller, I use a code sample from NestJS.
https://docs.nestjs.com/techniques/server-sent-events#usage

@Sse('sse')
  sse(): Observable<MessageEvent> {
    return interval(1000).pipe(map((_) => ({ data: { hello: 'world' } } as MessageEvent)));
  }

Expected behavior
I use a sample from the NestJS source, the result will be as follows:
https://github.com/nestjs/nest/tree/master/sample/28-sse

Additional context
I use the default template setup.
Perhaps there has been some configuration that caused the loss of the SSE data.