MacBook Air 2018 sound intermittently disappearing

The 'internal speaker' option will suddenly disappear - causing any audio devices using it (and the microphone) to go quiet. Sometimes they recover in a few seconds, sometimes the call drops - it's always extremely annoying as in a best-case scenario I have about 10-20 seconds of audio interruption - which is completely unacceptable.

I've been having this issue over the last couple of weeks - more and more noticeable because of the amount of conference calling I'm finding myself doing lately.

When connected via bluetooth, the connection rarely drops (although this does still happen sometimes).

I have reset NVRAM and SMC - the issue seems to keep coming back. I have also contacted Apple Support - who suggested that I try seeing if the issue is still there in 'Safe Mode' - when audio is disabled in Safe Mode....

This doesn't seem to be an isolated incident as the following threads show:

https://discussions.apple.com/thread/3008583

https://discussions.apple.com/thread/251267390

https://discussions.apple.com/thread/251262933

https://forums.macrumors.com/threads/2018-macbook-air-losing-sound.2227215/

https://www.reddit.com/r/MacOS/comments/eywmn4/audio_devices_keeps_disappearing_and_appearing/

I have collected a console log of when the audio device disappears and then reappears - although there doesn't seem to be much too revealing. It's linked here: https://www.dropbox.com/s/1i1qb2c3awnqtxd/audio%20dropping%20out.csv?dl=0