Alexa does not understand the names of the devices

Alexa device naming guidelines

• Do not use special characters (i.e., *(&%’#_) in the device names.
• Avoid typos or grammatical errors.
• Do not use conjunctions (e.g., and, or, etc.) in the device names. 
• Avoid using device names that are homophones of each other (e.g., Aaron’s Lights versus Erin’s lights).

For more information about changing device names, see Change a device name in the Amazon Alexa app.