Independent WebOS app can only access Web Sockets through iPhone

I'm developing an independent WatchOS app that uses NSURLSessionWebSocketTask to access Web Sockets. This works fine as long as the Apple Watch is connected to an iPhone, but when it's not, the web socket won't connect and gives an error that there is no network available. Using NSURLSession to access a web resource works fine though whether the watch is connected to an iPhone or not. Is this a bug or is there a way to get this working? Thanks