Hey Leonard,
Probably your broker has closed the trade because of the small margin left or the exit condition in the EA applied. There is such an indicator in the EA.
That is why you need to remove the EA after the trade was opened.
And that is why Petko suggests always using just 1 EA with the NLF at a time as a beginning, and when you get used to it, you can start using more than 1.
Cheers,