I noticed that if I turn on Do not Disturb on the watch it turns on, on my phone and vice versa. The same thing happens with Airplane mode. However I noticed a thread on Macrumors saying that turning the phones hardware mute switch to silent should also turn on mute on the watch. But this doesn't happen with mine. Even with my phone on hardware mute, the watches sound is independently set, and doesn't turn on mute on the watch. Is it the same for you guys?