GCP logs show function "Function execution took xxx ms. Finished with status: response error" whenever my header status code is not 200

As stated in the title, whenever I set my response header to be any status code besides the default (200), I receive a response error in my logs. This did not happen a few weeks ago so I am not sure why it is happening now. Another thread: Firebase Cloud Function finished with status: 'response error' said that the HTTP request of response of my function is higher than 10MB. However, I decided to just deploy a function (getTest) that is just

package foo

import (
    "net/http"
)

func GetTest(w http.ResponseWriter, r *http.Request) {
    // Status Code Test
    w.WriteHeader(201) // Testing with status code 201
    return
}

and I am still returned a 'response error'. Replacing any status code (201,400,404,500,etc.) for 200 in the above test code would result in a successful GCP log of status code 200.

Furthermore, GCP would sometimes automatically invoke the function again with a status 200 if the previous invocation ended in a response error as shown in photo #1. I say sometimes because I cannot consistently exhibit the issue. It is to my belief that during this re-invocation nothing in my code is actually executed and it just returns a 200.

Does anyone know the issue?

Edit: I also want to point out I only see this "response error" on Cloud Function Logs. On my API gateway logs, I see the correct status code the function ended on.