You mentioned that you are doing this switch in the macOS preferences, is this change by any chance in the HQPlayer settings itself? You mentioned this happens overnight, is the computer going to sleep during this time and being woken up again?
Thanks for clarifying this. What kind of mobile device are you using with Roon? It might take a few seconds to load but 1 minute seems excessive. Are you using the newest iOS version if you have an iOS device? Does reinstalling the Roon app help?
We recently released Roon 1.7 (build 500), can you please check to see if the behavior is the same after upgrading? If the behavior is still the same, I would appreciate a few screenshots to clarify the error state, thanks!