Anyway maybe I found a workaround. In case an error occurs when trying to play the movie, there is a maximum number of retries...
I have done this because my suspect is that, due to the CF-19 "poor" performances, the libraries aren't (fully) loaded when the movie is played.
I will keep you up to date whether this is or this is not THE solution, for anyone else's benefit.
Thanks to everybody!
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