I hope there's a fix soon, because I'm tired of having to force-kill the app.

I don't know what tipped me off that Facebook was the culprit but I was driving one day and my podcast went quiet, like a notification sound was about to happen. But nothing came and the audio stayed quiet for at least 30 seconds before I pulled over, opened the app list, and killed Facebook. Problem solved.

Also, coincidentally, I forgot to kill Facebook last night and when I picked up my phone this morning it was warm. Glad I remembered to leave it plugged in.