Is this behavior of the Right Hand Side (RHS) contents panel a nature of the theme?

[brtnfld]

We ran across the following type of behavior for our website as how this website behaves:

https://matplotlib.org/stable/api/matplotlib_configuration_api.html#backend-management

If you are at "Backend management", it has the expanded subsection below it. Now, if you click on the next major section, "Default values and styling", it displays "Default values and styling" in the main panel, but the RHS panel does not collapse the subsections in "Backend management", and there is no bar indicator in the RHS to indicate that we are at the "Default values and styling"

For our case, which uses the related sphinx_book_theme,

https://cgns.github.io/standard/MLL/api/c_api.html#file-and-library-operations

Suppose you are at "File and Library Operations", and then click on "Grid Specification". In that case, it will expand subsections of the previous section "Auxiliary Data" instead of the current "Grid Specification" subsections. I find this odd, but it looks like standard behavior from looking at other websites (like the first example), so I want to verify that this is expected.

[drammock]

that looks like a bug. In the Matplotlib site, if you click on "Logging" instead, it works as expected. possibly related to #1889, which so far nobody has had time/skills to figure out the cause of. If you have ideas for a fix, a PR would be welcome!