How Add Transition without Showing Previous Frames

Hello,

I created a key hold segment of a specific frame and extended the duration so that I could put a transition. However, when the transition is added it goes back in time and adds frames that are not part of the segment. I already extended that particular frame to make it more than long enough to span the transition, but it still "rewinds" and adds ealier footage when the transition is added.

Why does it try to fill the gap for me instead of just applying the cross dissolve transition to the segment as it is? How to do this?

Thank you