On my iOS device it does the same. I use Apple Music. I guess it’s because renshuu plays audio when you review stuff, so your phone must think “audio focus should be on the app that’s currently on the screen rather than a background app”. I’ve not found a way to get past this.
This is something that I need to fix - it is unfortunately harder than it should be due to the way that renshuu was built, but it is an issue that I'm aware of.
Basically, the audio in renshuu stops the background music. Because renshuu is a blend between a true native app and a web site, it does not have as clear of a path to fixing this as other apps do.
I apologize for the inconvenience!
This is not ideal, but you can always disable the auto-playing of audio after a quiz question so nothing plays automatically unless you request it.
