The problem was caused by the movie: evidently Rocketman ends with a data pattern that I had not encountered in the movies I have so far examined.
Thanks @ragico for pointing this out.
I invite those who have downloaded version 0.0.2 to download it again (original post HERE)
RESET_9999 has reffered several times that my files (with a Single Track) didn't work on the X700 (when muxed inside an mp4).
Maybe the problem also occurs with the ts container.
My tool is addressed to owners of the new Shield 2019 (BL + EL + RPU) or Fire Stick TV 4K (BL + RPU).
If you own an X700 you should not use my tool but you should create a Double Track file (as RESET_9999 explained HERE)
Ask him for more information!
Thanks for reporting back