Recent drop in device volume when using AirPlay or Bluetooth

Has anyone else seen a recent significant drop in AirPlay volume? Both my mini and my 16 pro max are both doing the same thing. I have a Hifi Rose streamer which was just returned from service. I don’t think it’s the Hifi Rose because both Bluetooth and AirPlay are less than half the volume it should be. But a PC Bluetooth is quite loud, and unaffected.