This problem randomly happened to me Jan 2023 and I was able to resolve it by replacing the battery myself after reading this forum. First I downloaded the UE app, so I could update firmware and view the battery percentage. It was at 0%. The pushing the Up Volume quick fix trick from this article didn’t work for me so I ordered a new battery kit for $30 and replaced it myself. At first it was still turning off after unplugging, I was so bummed. But then I tried the volume up trick and when I unplugged it, still playing now! I’m so happy. It was probably just a dead or faulty battery but I’ve had this speaker for like 3-4 years and it was not new when it was given to me so I am so satisfied with this fix. Thanks everyone!