I've been successfully using the Android phone app to control my Roku 4620x device until last night. The outage continues today. I have rebooted both devices and still no luck. After rebooting both, I briefly had connectivity, about 5 minutes, and then the app could no longer find the Roku device.
About 2 months ago we updated our internet to fiber with 350 mbps both up and down and excellent signal strength. Both devices are on the same wifi network.