The active state on TOC links is buggy

[xelaint]

🐛 Bug report

Current Behavior

The active state on TOC links is buggy.

In this video example, scrolling a little past the DaffProgressBarComponent title jumps the active state for the TOC link to Directives, even though the content in the DaffProgressBarComponent section is very long.

https://www.loom.com/share/1281af24f944410aa3bd2023edb3e5ff?sid=ad4debc7-528e-4aa6-ac45-855bf0b54e5b

Expected Behavior

Minimal reproduction of the problem with instructions

What is the motivation / use case for changing the behavior?

Environment

Daffodil version: X.Y.Z
Angular version: X.Y.Z 

 
For Tooling issues:
- Node version: XX  
- Platform:  

Others: