I don't remember properly but I think on my first 787 flight (ARN-DOH) in J there was no problem with the screen.
Could select language, use the menu and start movies. Found the hand device very unresponsive and laggy so I didn't use it.

On the return flight I noticed the same as you. Couldn't use the touchscreen unless a movie was started. So I had to use the hand device and start movie.
As soon as the movie was running, it was no problem to use the controls on the screen. And I think it was also no problem to use the upper menu (go back to main, go to flight map, etc.)

In my opinion best IFE was on A380. Screen had no problems and the hand device is very responsive and working like it should.
Ease to navigate, select movies and start on screen.