Streaming tweets with Twitter API returns NULL despite successful authentication

I have set up my Twitter API

consumerKey <- "xx"
consumerSecret <- "xx"
accessToken <- "xx"
accessTokenSecret <- "xx"

setup_twitter_oauth(consumerKey, consumerSecret, accessToken, accessTokenSecret)

This was returned (which has been successful before)

[1] "Using direct authentication"

Now, when I am trying to stream tweets for a certain amount of time, it seems to be successful as its running but it returns the file under values and not under data and shows "NULL"

btw21test <- stream_tweets("#BTW21",
  timeout = (60*5),
  parse = FALSE,
  file_name = "BTW21.json"
)

## read in JSON file
btw21test <- parse_stream("BTW21.json")

NULL

Does anyone know if this is because of the Twitter API? I have used the exact same code successfully in the past. Thanks!