How to fix error when handling click event on empty links?

Question

Frontend

Good morning!
The last few weeks I've been facing this interface:

It has been completed to the end and I still cannot solve the issue of implementing interactivity when clicking on a menu item.
Depending on which link number is clicked, the algorithm itself switches to the element under the selected number, but the opposite happens.
What have I allowed in the code? How to finally solve the problem itself? Thank you in advance!