Help with iMovie automatically changing durations of clips

Sometimes, when I change the duration of a background, a transition, or rarely, a clip, imovie changes the duration of clips nearby. For example, sometimes when I change transition length from 0.2(default) to 3, then it changes other clip lengths around it. This is annoying when im trying to have everything a perfect length to have my audio track end when a certain part starts.

Ex.

1. I lengthen the duration of a transition.

2. The title and image right next to it gets shorter.

Why does iMovie do this? Is there any way to stop imovie from doing this? I'm guessing it does this because it overlaps two pictures/clips and it only shows wht isnt getting overlapped. But sometimes, it changes in a way that this couldnt be the case. Any suggestions on how to stop this?