The most common reasons are that Wi-Fi may not work properly then your Alexa does not respond properly and their voice command is also not....
https://www.smartspeakerhelp.com/alexa-not-working

Sometimes you face issue when your Alexa device is not connected to Smart TV. In that time check if your Smart device is compatible with....
https://www.smartspeakerhelp.com/how-to-connect-alexa-to-smart-tv