I have been using my home speaker 500 with my Amazon music account for over a month with no problem but today it has an error when I ask it to play a station. The error is SC4105. It asks me to check the network connection and power supply. I asked Alexa if it was connected to the internet and it said it was. I can play other music services on it with no problem. I tried to remove the Amazon music account, and reload it. I tried resetting the device to factory default. The problem remains.
Maybe, try using your Amazon music account from another device such as your computer, etc. There might be a problem with your Amazon account.