I Have a Samsung UN65F7100AFXZA TV. I have connected a Chromecast dongle to the HDMI4 input on the rear of the set. I would like to apply a custom name to the HDMI4 input but when I pull up the name-edit function, the only options are the stock list of names built into the TV. All of the other HDMI inputs gave me the option of entering anything I wanted by using a keyboard but not of this one. Am I doing something wrong?