Hoopla trouble with CarPlay

I recently tried to use my Hoopla app through CarPlay via Bluetooth on my iPhone 13 mini to listen to an audiobook from my library, but unless I physically open Hoopla on my phone, the CarPlay app won't start my audiobook. The app opens, and I can see the book I want to play, but the cover art doesn't load, and the book won't play when I press the "play" button on the car's screen.

If I start the book from the app on my phone, the cover art loads, and I can then pause, resume, rewind and fast forward from the car's screen. All my other audio apps (Pandora, TuneIn, Spotify, Apple Podcasts) work seamlessly from the car's touchscreen over Bluetooth, but Hoopla does not.

My phone and my car's software are both up to date, and there aren't any settings in the Hoopla app nor in my car's CarPlay systems that I can find to try to correct the issue. Any help or advice on the subject would be much appreciated!