Are you experiencing Wi-Fi connection issues while using your Roku 3?
Roku 3 will grab the same Wi-Fi channel as the nearest Wi-Fi access point (e.g. yours). It will broadcast a Wi-Fi Direct SSID DIRECT-roku-123-A2 or “Hidden” on the same channel. It will increase its power to stay above your access point if you up the transit power.
The Roku has interference mitigation enabled by default. This is technology which deliberately disrupts traffic to nearby Access Points to attempt to improve local traffic.