Echo, Fire TV Stick remote, and Fire TV Android app.

[paulmorin]

New revelation. Fire TV Stick remote Home button will make the TV HDMI input switch to Fire TV, sometimes. Once the TV is turned on and the HDMI input for Fire TV selected (and switched back), the Fire TV remote Home button will cause the HDMI input to switch to Fire TV. Interestingly, the Android Fire TV app Home button does the same thing.
Note: When you first turn the tv on pressing Home (remote or App)  will do nothing. It has to be after the initial switch to Fire TV input and then back to normal TV HDMI input.

So, my question is, why doesn't ECHO "Alexa Watch Fire TV" switch the input since the remote and the app can???

[mike27oct]

Many remote buttons for a device can control a feature on other devices, because there are only so many frequencies available for remote controls and devices.  You just hit a same frequency for the TV HDMI switch.  Don't get too excited about this, because one day you will press a remote button for one device and do something on a different device and you may not like what it does!  This is more of a PITA than it is a cool "feature".

[paulmorin]

Actually, I don't think this is a cool feature. What should happen is that Echo should issue the same signal to Fire TV that the Home buttons do. You could call it a bug. It really is an action that Echo should perform to stay in step with the remote functions.

[mike27oct]

This is not a "bug", it is a coincidence.  Don't sweat it, but if you want to report it to Amazon as a bug go right ahead.