Hi Paul and Joshua,
For some reason I haven't been receiving updates to this post so only looked this morning. I added, but no change. However when looking at the inspector I did notice that with the inspector on there was no jumping. It looked like something to do with the height to make the image full screen.
Further viewing of the inspector does reveal 2 height settings for the slide. One for 505px and one for 605px. Could it be that the slide is jumping as it goes to the dominant setting? Image attached of Inspector where you can see the two settings. I can't find either for height in Zentools, only 100%.
Cheers,
Ric