Interesting, as in my signature, I still have my 9002 from its UK availability in November 2017 - which I’ve had no audio issues with. I don’t use the TVs speakers as my AVC uses audio via HDMI ARC from the TVs terrestrial tuner and built in Apps. All other video to the TV comes from the audio being removed by the AVC before getting to the TV - i.e. from 4K and high end sound from Blu-ray, Apple TV, Prime Cube directly connected to the AVC. When not wanting to fill the room I also use Optical output from the TV to a soundbar as the quality of the TVs speakers is so poor.
So, I guess I’m lucky the way I use audio works for my setup and, hopefully, I remain lucky with changes of kit… like the so far elusive 55OLED936.
P.S. I do have one serious issue as I was led to believe UHD HDR ‘HLG format’ was available from HDMI, unfortunately when I was able to try and use it, it doesn’t work. At least, after 18 months without it, the built in BBC iPlayer App now has HLG. Some folk were recently offered a new 806 that can do this, my support request is still ‘under investigation‘ after two years - so my confidence in what Philips say is low.