After doing all that, did you remember to change your language back to US English? Because language selection affects the features too. I know coz I am in US but use UK English and some features does not work just coz I use UK english in here - US, like the chat feature, giving me error.
I finally went back to US english to have the full Alexa experience. Also noticed, I don't have to repeat my commands several times just to turn/off my lights.
Honestly, I think your problem would have been solved if you just changed back to US English, instead of doing all that you did.