Adobe Indesign CC 2018: Export to pdf does not maintain Indesign file layers structure
Creating interactive pdf in InDesign may require controls to be placed in a strict vertical sequence.
Exporting to interactive pdf from InDesign re-orders the layers and elements within those layers. This may break the functionality of the original structure as some buttons which control the appearance of others may no longer be accessible. The structure then has to be modified in Adobe Acrobat which is time consuming and awkward to do.