Unit Testing ReactiveCocoa SignalProducer keeps coming back interrupted

Question

Ive been unit testing ReactiveCocoa Signals and Producers using XCTest expectations for a project im working on. For one some reason (I suspect after a pod update) my tests started failing and SignalProducer events are returning the interrupted value and never actually sending the successful value. If I set breakpoints everything seems to work fine in the actual task its just when it gets to the observer lifecycle where i dont see the value passed back. Using XCode 9.4.1 ReactiveCocoa (8.0.0) ReactiveSwift (4.0.0) Result (4.0.0)

let signalExpectation = self.expectation(description: "Signal Expectation")   
let aSut =  SignalProducer<Data,WXClientError> { observer, _ in
            let task = URLSession.shared.dataTask(with: url!) { (data, URLResponse, Error) in   if let Error = Error {
                    observer.send(error: WXClientError.webFailure(description: Error.localizedDescription))
                } else if let httpResponse = URLResponse as? HTTPURLResponse {
                    if httpResponse.statusCode == 200 {
                        observer.send(value:data!)
                    }
                }
            }
            task.resume()
        }

        let testObserver = Signal<Data,WXClientError>.Observer{ (event) in
            switch event {
            case let .value(v):
                print("Test Observation value = \(v)")
                signalExpectation.fulfill()
            case let .failed(error):
                print("Test Observation error = \(error)")
            case .completed:
                print("Test Observation completed")
            case .interrupted:
                print("Test Observation interrupted")
            }
        }
        aSut.start(testObserver)  
        self.waitForExpectations(timeout: 5.0, handler:nil)