I’ve been watching my roku for a bit now and suddenly when I turn my tv on it says resolution not supported change resolution of the external device. I’ve tried everything I’ve seen on the internet and more to get to use my roku again. Overall disappointed in product
Roku recently added a "power saving" option under Settings->System->Power that seems to affect the HDMI handshake for some TVs. See if you have the setting and try disabling it.