Host can hear other players interactions e.g. building, turning jetpack on and off, etc.
As me and some others have noticed that sometimes (not sure if it happens with multiple players in the same game or only when their are two players) the host can hear most of what the second player does, like building or sometimes welding
It doesn't seem to go away even after reload, and this seems like an old bug that was common a while back. hopefully this is a smaller and quick fix that can be included quickly.