try unplugging it for about 40 seconds. Something to consider, the longer you use alexa, the more comfortable you get with it and will tend to get lazy with the commands. You may not put enough of a pause between the wake word and command, say everything too fast, too low, or whatever. Just pay attention to your commands and see if that is the problems. It happened to me and I had to adjust the way I was giving commands after a couple of years.