You cannot remove a device from the Cast list. That list is dynamic and
always shows you every device that is currently available and ready to
receive a cast. The only way around that is to either turn off the
device or put it on a different network....
I would expect that you would connect the soundbar to the TV and let the
TV move the audio. Just like you would do if you were using a cable-box
or game system. In theory, you can connect the soundbar to the Streamer
using Bluetooth. But, otherwise, ...
Doing a Google Search on "change network password on Silo TV" turns up
this:
https://www.heysilo.com/a/support-portal/silo-device/changing-wi-fi-network-on-your-silo-device
Though it does not help you with your current situation, I'm sorry, I
would strongly suggest that in the future you do not use the TV's USB
ports to provide power. Google does not recommend this because most TVs
are designed to only expect data-stick...
To add to Moralevicente's excellent information.... Hotels that have
open networks often turn on Isolation (devices can talk to the hotel,
but not to each other) to protect your device from being attacked and
hacked by another device on the same netw...