No live audio or notifications, but video is OK

Ring doorbell 3. I installed the doorbell brand new about two weeks ago and it has been working absolutely fine. I get notifications of motion and when someone rings the bell. This morning when I checked the live feed, I could see video OK but no audio. Likewise no motion detection/notifications. When I started to listen to the live feed I heard a blip of audio then nothing. The bell is hardwired using the official Ring PSU. Battery is at 100%. Bell is connected via a Chime Pro. WiFi isn't an issue as I can see live video, just no audio. Fortunately when I removed the battery and unplugged the PSU, it reset and when repowered all is working again. It has knocked my confidence a bit as up until now it's been rock solid. Is this 'the norm' with Ring doorbells? What could have caused it?