Do you assign static IP to your Emby server on your router? Or is this using dynamic IP assignment for your server? This might be the problem. The Roku no longer has the correct IP address associated especially if this is done using PIN/Emby Connect. This would cause the Roku app to believe the Emby server must be awoke from sleep. So you might see the Wake option presented and it says it cannot find the server. This is due to the IP address changing on your router that points to your Emby server. If you set this as Static on the router so it never changes this would help PIN/Emby Connect stay on track. If you use manual connection it would do the same thing. But you could enter the new host/ip and port into the manual server entry and then get past this.
Edited by speechles, 26 April 2019 - 10:41 AM.