3D FlipBook - Alignment problem

If you look here: https://ebps.org.uk/3d-flip-book/pteridologist-2019-part-6/ and page forward you will see htere is an alignment problem Also I loose all the information in the left-hand margin If you go back to the home page https://ebps.org.uk you can see what should be there Could you help me to sort this out? I really like the plugin apart from these minor problems