Notification pops up `No device detcted` randomly and audio and video stops

I am using EnOs Kde Plasma. I use my bluetooth speaker for audio. When I am watching video lately a random notification pops up on the center sayig no devices found and goes audio. I have to restart to restore the audio. The bluetooth will be stayed connected. The video won’t play. I am talking about the web (youtube/netflix).

Any idea what’s hapening ?