When switch to HDMI input when connect to my Apple TV, I got noise signal screen. I have check the hdmi cable has no issue. However, after I unplug Mopro power and restart, the issue not happen. Do you know the reason?

When switch to HDMI input when connect to my Apple TV, I got noise signal screen. I have check the hdmi cable has no issue. However, after I unplug Mopro power and restart, the issue not happen. Do you know the reason?
