Dolby atmos suddenly stopped working on my apple tv

Hi everybody,

today I was watching Netflix on my Apple TV - and half way through a show the audio stopped although the picture continued. After a while I changed the audio setting from Dolby Atmos to stereo and back was the audio, albeit in lesser quality. What strikes me as odd is that for approx 2 months this setup (including Philips TV (7300 series) soundbar (HTL 3325) was working fine. Any clue what suddenly causes the audio to go mute? I’d be happy to use the better audio option.