It's because of [this line](https://github.com/cdzombak/thingshub/blob/bb078f9b09396bec2f0137214366cd9caa1adbed/thingshub/CDZThingsHubApplication.m#L29) – your `authClientSignal` is mapping all next events to *return a signal*, namely the one from `+[CDZGithubAuthManager authenticatedClientForUsername:]`.