The best method is to unplug the multi-HDMI switch and plug in each device, one at a time, in the same TV input. Set up the devices using the settings in your Firestick, Cube, or Fire TV. Plug all devices back into the HDMI switch and test the results. If each device has a name, it should go to the correct input for the specified device, as long as your HDMI switch has the auto feature, and it works correctly.