After Effects changing clip dimensions



I'm working on a music video which requires A LOT of special effects.
Each time I "replace with After Effects Composition" and make an edit to a clip, the edited clips/frame dimensions appear slightly larger than it was before working in AE. However on the Effect Controls in Premiere, the dimensions appear unchanged. How can this be? Tried scaling to size, but it worsens the issue. What am I doing wrong?
Recap:
Each time the edited clip comes back into Premiere Pro (from AE) , it's larger , by about a half inch than it was originally. I've wasted hours upon hours already trying to figure this out.
