For me, it is a little less specific to reproduce. I don’t necessarily have to start any stations. Sometimes just opening the app will have it freeze.
I will mention, I’m on iPhone X, not sure if that makes any difference … but seen a similar issue with another app after they updated it to allow for the larger screen.
I would say that 9 times out of 10, I can get the “freezing” to happen from just normal use. But like Jeremy, letting the screen sleep and then unlocking it back into the app is almost surefire way to do it.
Hope any of that rambling gibberish helps. 🙂