Hi, hopefully you have found a solution to the autoplay issue by now, however, thought I’d post this for anyone currently struggling.
I recently bought a Mag520 box and autoplay was an issue. It wouldn’t give me a chance to scroll through any channels and would instantly play the channel the ‘play’ icon was on.
This issue was resolved by going to Home > Settings > Video > HDMI event reaction. Change this setting to 5 minutes.
This then gave me time to look through the channels and double press ‘ok’ to select the channel I wanted.
Hope this helps 🙂