When listening to Spotify through my Denon Heos 1 using Connect... if I use the volume buttons on my phone to change the volume, the volume takes a few seconds to respond. When controlling the volume on my laptop, I can click anywhere along the slider, but it only changes the sound as if it were split into 4 sections. For example, there are specific points on the slider where the volume changes, so I can't make it play between what I would deem as too quiet and too loud for listening to while working.

My usual solution is to then use the Heos app on my phone. This shouldn't have to be a solution, the volume slider should work as it used to. However, I've just gone on the Heos app to provide finer control to the volume, and it cranked the volume up from close to quiet to louder than what is comfortable. All without touching anything, I merely opened the Heos app!

This never used to be an issue! The Spotify app used to control the volume as finely as the Heos app. Now it doesn't, and it's now leading to me nearly blowing my neighbours eardrums! I am assuming it is Spotify as they have provided more recent updates, Denon haven't updated since the issue started.

Why's this happened? What can I do to solve it? What are Spotify doing to solve it?

I'm running the latest macOS and iOS as well as all available updates for Spotify and Denon.