RxJS in AngularJS Services

I’m learning RxJS and am trying to implement it in one of my existing applications. First thing I am trying to do is remove rootscope.broadcast/emit methods and replace them with BehaviorSubjects. This has worked fine if those events are subscribed to inside a controller. However, if I try to subscribe to those events in a service, they never fire. I can move the exact same subscription into a component/controller/etc and it works fine.

Is there a reason for this or should I be able to do this and I am just doing something wrong?

RxJS in AngularJS Services