Audible app not going back to current book

In the last few weeks, I've encountered some strange behavior from my audible.com app. Previously if I switched to another app or if a book was interrupted by a phone call, re-opening the app also opened the book I was listening to. Now I am given the library screen where I have to tap on the book I was playing. Not a major problem, but if I am listening while walking or in the car, it is distracting. I am wondering if I have somehow changed a setting, though I can't find anything that seems relevant.

I've also had a problem when listening to a book using bluetooth headphones when a call comes in. Sometimes, when I resume the book, my Astro Player app also opens and whatever song I had previously had marked starts playing as well.

I've sent two requests to Audible customer service, but no response other than the form email that they will get back to me within one business day.

Can anyone offer a suggestion?