I was battling with this for ages and it’s definitely an annoying bug – another work around I’ve found is once you’ve added your 2 keyframes, click on a random point between the two keyframes and then add another keyframe. Disable it, add it again – do this a few times and you’ll notice the picture shifting position. Keep toggling the frame on and off until the picture stops moving.
For some reason this works!
TASH JONES | Producer/FCPX Editor