Getting Dolby Atmos on Apple TV 4K, LG TV and Sonos Arc

I’ve recently purchased a new LG OLED CX series TV (2020), which comes with an eARC HDMI port, and a new Sonos Arc soundbar to accompany my Apple TV 4K. After lots of tweaking and reading online forums I’ve managed to get Dolby Atmos working perfectly on the Sonos Arc from most of the main streaming apps on the Apple TV 4K (Netflix, Apple TV+ and Disney all fine; Amazon Prime not working so far). Produces fantastic sound for movies and TV shows. The main issue was that the TV settings default is for eARC to be switched off and for passthrough also to be switched off; once these were both switched on and the correct sound settings were in place on the Apple TV, it all worked fine.

However, so far I’m unable to get music streaming apps on the Apple TV 4K to stream on the Sonos Arc (either in Dolby Atmos or regular stereo). I have the Tidal App installed on Apple TV and a Hifi account which provides Masters that should play in Dolby Atmos format but doesn’t. Instead I get a broken sound, where every second beat is skipped, like a scratched CD or record in the old days. Even the Spotify App, which doesn’t offer Dolby Atmos, has the same issue. Any solutions?