Unfortunately, the issue is known, the executable rootbrowse does not work on MacOS. We are sorry!
The long technical explanation: The operating system itself prevents us to spawn an additional thread, which updates the GUI and therefore you see it as frozen. Butwe enabled the GUI in the Python prompt (as you found out!) and in Jupyter notebooks, because there we can attach the “event loop” of the GUI to already existing mechanisms. For example, the Python prompt has the PyOS_InputHook mechanism, which you can use to attach callbacks such as the update of a GUI. At the end, it’s a technical limitation we could not get around (yet?) on MacOS. Suggestions are very welcome!