I have found that for Good Night, I needed to add two routines, depending on how Alexa heard me.
Both are the same but with "Good Night" and "Goodnight"
When I say "Alexa good night" it can here is as either "Good night" or "Goodnight" and either just reply to me saying good night but do nothing, or sometimes it hears it as a command and turns off my lights.
Hence adding 2 routines, covers it