I have successfully mirrored my iPhone to my tv via the Roku screen mirror app But the videos I’m trying to watch (workout videos), are extremely delayed and slow, making it impossible to do a workout. Help?
It is up to your phone hardware and wifi how well mirroring works. If the videos are files stored on your phone you might do better sending with the roku remote app. Or, if you have a computer available, use the Plex or Emby servers to send to the corresponding roku apps. If they are streaming from the internet, try to find a native roku app to access them.