Same thing here. Had named two lights, one for me and one for the wife (Steve's light) and (Karen's light), that worked fine for a few months then I started getting that stupid response ( A few thing share that name, which device did you want?). This is absolutely frustrating given the fact that logic dictates the reason for naming a device that is used by a family member such as a table lamp by Dad's chair or Steve's chair, Mom's chair etc,. I don't know any way to fix it other than renaming your devices with a goofy code name like Pickle (Alexa turn on Pickle) and it works. Even Dingle-berry works, or Aardvark. So in the meantime I'm naming my wife's light, "Star light" and mine "Moon light" I don't expect a fix overnight, or for Alexa to tell me it's okay the give a device a persons name... well except for Alexa.