Galaxy S7 Edge *automatically* connecting to ChromeCast device :(
My wife recently got a new Galaxy S7 Edge (AT&T branded), and it seems to have a small (but still frustrating) bug (or perhaps a "feature"): When another family member (on the same home WiFi network, of course) is currently casting/using the ChromeCast, and then my wife goes to watch a YouTube video, the person originally using the ChromeCast is disconnected (because my wife's phone seemingly automatically connected to the ChromeCast device), and my wife's YouTube video is sent to the ChromeCast, where she can't see it (because she is often in another room).
No other family members' Android smartphones seem to have this problem, and my wife's previous phone (Galaxy S4) did not have this problem, so clearly it is a problem with that make and model smartphone. If that is true though, then other owner's of that smartphone probably have the problem as well (whether they know it, or not). Has anyone else had this problem? My hope is there is just some ChromeCast "auto-connect" option, that is usually disabled in Android, but in the (latest/current) ROM for the Galaxy S7 Edge (AT&T branded) has that option enabled, and I simply need to disable it. If it matters, the ChromeCast device involved is a 2nd generation one (i.e. not the ChromeCast Ultra, and not the 1st generation Chromecast).
Thanks in advance for any assistance!