html5 semantic elements, site scrolling does not work—advice for site authors?

Describe the bug
Scrolling doesn't work on a site. j/d do nothing, u/k scroll up by the same tiny increment. g/G do nothing.

I am asking here, so that someone who knows the codebase well can quickly answer why it's not working, which I can then link to the site's authors.

I would love even a short list of ways that sites implement scrollable sections, and how vimium accounts for all these. Other site-specific issue, unrelated, but I know these must be a burden #3134. Could a site-specific label be offered in this issues list? Perhaps this issue can also be seen as a request for an FAQ, or debug guide, or links to a list of site-specific issues that have been resolved or closed over time.

To Reproduce
Steps to reproduce the behavior:

1. Go to URL https://determinate.systems/ or https://determinate.systems/posts/flake-checker, or personal blog by same author, https://grahamc.com/blog/nixos-on-framework/
2. Attempt to scroll. Click on or focus the page, attempt to scroll. Scroll down manually, notice minimal scroll up acions.

Browser and Vimium version
Vimium: 1.67.4. Tested with chrome store version (& run with verison customized for iframe handling)
Browser: Brave 1.52.122 Chromium: 114.0.5735.110 (Official Build) (x86_64)

Reproduce the scrolling behavior on determinate.systems, its flake-checker post, and grahamc.com/blog/nixos-on-framework/ using Vimium 1.67.4 in Brave. Determine which site-specific scrolling patterns prevent j/d, u/k, and g/G from working, then document the cause and actionable guidance for the site authors or a relevant FAQ/debug guide.