The TOC in my generated project is not navigating to the correct subfolders

The TOC in my generated project (Multiscreen HTML5/Andriod (Desktop) layout) is not opening to the correct sub folders.

For example, when selecting a Level 1 folder (say the one highlighted in orange), it will jump to a Level 3 list of topics in a completely different level 1 structure (say the list highlighted in green)

Level 1

       Level 2
              Level 3

              Level 3
              Level 3

       Level 2
              Level 3

              Level 3
              Level 3

Level 1

       Level 2
              Level 3

              Level 3
              Level 3

       Level 2
              Level 3

              Level 3
              Level 3

I have looked at the TOC report, everything is fine there, the TOC in roboHelp looks fine as far as I can see.

I have noooo idea how to fix this!