If I try to connect a second remote. the first one is disconnected. If I could use a Hub, Switch, or router to achieve the result that either remote could use the voice control it would be much simpler for my grandparents who are over 85
No such thing that you are looking to get. How the remote connects is a feature of the TV talking to the remote, there are bluetooth range extenders, with pretty poor reviews, but they don't do what you want it to do.