I have been in discussion with the shop where I bought my GX 80 about the audio quality. I know it is only internal mic and that the 1.2 upgrade resolved some IS disturbance - but is the audio as shown in this clip as it should? https://youtu.be/4Bai-gzKzIs

That doesn't sound like mine though I have to say I have had some very bad audio from the GX80, you clearly hear the IBIS grinding in the background but I have had occasions where some kind of autogain kicked in making the audio sound very muffled and totally useless.

I think mine sounds more like dust on the microphone electronics than a typical amplifier humming.

It's definitely not "normal".