Trills extending

I'm working in something at the moment that has some long flute trills, and I'm using the trill line in the lines section of the palettes. When I go to the playback to hear it, and the notes (without a trill) will hold out for almost twice as long as what I inputted. Everything I saw regarding the matter mentioned nothing about a trill, and said to adjust things on the synthesizer. I adjusted everything on it to what people have said in the past, with no success. If anyone has had this problem and knows how to fix it, please help me.