Perform a “hard reset”. This can be done by pressing the volume up (+), the volume down (-), the Bluetooth button, and the power button simultaneously. Hold for approximately 15 seconds. I recently had this issue and now my speakers are working fine. Hope this helps!
I just spoke to UE customer service. I had to perform what is considered a “hard reset”. Press the volume up (+), volume down (-), the power button, and the Bluetooth button for about 15 seconds. My speaker is now back to normal. I hope this helps someone who might have the same issue.