Taxonomy

Hello,
A taxonomy called “RACI Category” has been created for the Procurement webpage. It is a manual that guides different public on best practices. On the webpage, it appears as a menu on the left and the text on the right. You can click on the button “Next” or “Previous” to move from one chapter to the other. I have just created a RACI called " Technical officers in charge of procurement procedures > 50kCHF" with a menu with 4 chapters. Everything seems to work fine but the second chapter is always skipped. That is, when I click on next, it always goes from “List of Acronyms and Definitions” to “Conducting a procurement procedure”. I have tried to add a new test chapter but it is skipped also!
Could you please help me? I don’t know what else I can do.
Here is the link to the page RACI Matrix | Procurement and Industrial Services Group (cern.ch)

And here is a screenshot of the RACI: