I can hardly believe I'm writing this, but the most recent app update has reintroduced a bug I complained about on here a year ago, and which was subsequently fixed.
I have all my speakers grouped together and mute/unmute them as I move around the house, because it's easier than grouping/ungrouping them. I don't want them all on all the time, as it disturbs my neighbours.
Following the most recent app update, my speakers now all unmute themselves every time I change the group volume (even if I'm turning it down!)
Why? How could anybody think this is a good idea? When will this unwanted functionality be removed (again)? More generally I am so sick of Sonos needlessly dicking about with things which work fine as they are. God knows if they want to change the app there is a long list of things which don't work properly - it's a dog's dinner.
It's clear to me that Sonos have learned nothing from the S2 app debacle.

