Maintaining dimensions when replacing an event video

Hello, I’m struggling to figure out how to maintain dimensions when replacing an event video. I have dimensions locked but the new video ends up in the same upper left corner position on the stage but at 100%. I would like it to replace the video on the stage and maintain the dimensions of the video it’s replacing. I’m working in Captivate 2019. (I have searched for this answer and haven’t found any results.) Cheers, Brian