Maybe you should contact the manufacturer.
lol
Try a different HDMI cable maybe, or factory reset if that doesn't work. That isn't an Android TV box so I doubt you will get much help in this sub.
Had this problem with the Shield. You probably need a newer HDMI cable like i did. Look for HDMI 2.0 or 2.1 You could also look in android settings, and try lowering/raising refresh rate.
It does this all the time that it's on, when it's booting up, and when it's in any app.
/AndroidTvBoxes