I'm using the power adapter that came with the Roku and tested using another power adapter that can supply 2 amps. The Roku still returns to the Home screen with both power supplies. The device is set up with the router only 3 feet away and other than having to reboot the modem and router occasionally, all other devices work normally, except the Roku.
The software got updated to version 13.0.0 a few days ago but it hasn't changed the outcome.
Tried a factory reset and still no success. The Roku plays for less than 5 minutes and returns to the home screen. Not much good for streaming video but at least it can be used as an audio streamer for now.
