Thanks for the post.
Since you've tried two different device, this would lead us to believe this is not a device issue, but rather possibly a network issue. Have you tried connecting your Roku TV to your network with a wired connection to see if you are able to resolve the issue? In addition, have you tried connecting the Roku device to an alternate wireless network, such as a mobile hotspot, to see if you can setup and activate your Roku device?
Please keep us posted what you find out.
Roku Community Moderator