Roku ultra suddenly saying resolution not supported *every* time we turn on the TV. Started 3 days ago. We've had the Ultra about a year, and are using it on our Visio tv. We've occasionally had this happen before but it was usually an isolated incident. I've checked the Roku system settings for updates and we don't have any that need to be done. The only way to clear the message and get Roku to work is to restart the device. Resolution is set to Auto in settings.
Settings > Display type
Try setting this to your tv's actual resolution instead of the "auto" setting.