Hub dropping off line

I live in the United States, I have a Smart Things Hub Ver3, it is connected to my AT&T Router, The Hub for no reason has started to just “go offline” for no reason, no body touches it, the light just goes red and the hub goes “offline”. Now it is even dropping off with the light still green. I then have to go and unplug it and wait for it to reconnect. Can anyone tell me why it keeps just dropping off.

…usually it’s network connectivity.

I understand that but it has worked just for for about two months, now all of sudden it started

start with the basics…

  • replace the ethernet cable between hub and router/switch
  • plug into a different port on the hub/switch (if possible)