Hello, I let you the firmware of the H20, it was very dificult to obtain, i share with you, all the tools for unbrik it because i had the same problem but no ones give me a solution, all the firmwares where bad, yo have to put it in maskmode to unbrik it with the factory tool, i let a guide but in spanish in the folder in mediafire.
https://www.mediafire.com/folder/b5oi1gd9cz2zj/H20_ANDROID_TV_FIRMWARE_10