Pan and zoom changes my still duration

I've already arranged all my still images I wish to use in this video to be shown for the exact duration I want. I now want to add pan & zoom to each still, but adding it changes the duration and I really don't want to manually set the panning time for each image. How can I fix this? I swear this has never been a problem before so something must have changed. All I want is for the pan and zoom effect to not change how long the still will be shown, as I have already set them in the timeline.