Is it possible to prevent casting when on a shared network? I use the hospital Wifi to connect my roku and people in the hospital seem to have a need to cast their YouTube videos onto my call room TV.
Well its up to them to not cast.
Short of that I can advise you to log into your Roku account....
Go to MY ACCOUNT
at the bottom of page change the name of your Linked device to
something like:
PLEASE DONT CAST HERE or
ROOM xxx ONLY Please
I'm surprised you can cast to anything on the hospital WiFi. Public access points are usually configured to block devices from seeing any other devices on the same network. Is this something you've actually accomplished?