ERR_UNHANDLED_REJECTION when using defer

[merthanmerter]

Hi, I just can't figure it out. When I throw error at the deferred data application crashes with below error.
If I simply return an error Response, then the Await element won't understand there is an error.
I'm not sure using process.on('unhandledRejection', (reason, promise) => -1); in entry.server is a good practice.
Any ideas? Appreciate the help.

[UnhandledPromiseRejection: This error originated either by throwing inside of an async function without a catch block, or by rejecting a promise which was not handled with .catch(). The promise rejected with the reason "#<Response>".] {
  code: 'ERR_UNHANDLED_REJECTION'
}