Can't evaluate field RegularPagesRecursive in type page.Site

I have a navigation dropdown which should list recent articles:

          <li class="nav-item dropdown{{ if $is_blog }} active{{ end }}">
            <a class="nav-link dropdown-toggle" href="/articles/" id="navbarDropdown" role="button" data-toggle="dropdown" 
              aria-haspopup="true" aria-expanded="false">
              Articles{{ if $is_blog }}<span class="sr-only">(current)</span>{{ end }}</a>
            <div class="dropdown-menu" aria-labelledby="navbarDropdown">
              <a class="dropdown-item" href="/articles/">All articles</a>
              <div class="dropdown-divider"></div>
              <div class="dropdown-title">Recent articles:</div>
              {{ range where .Site.RegularPagesRecursive "Section" "articles" | first 20 }}
              <a class="dropdown-item" href="{{ .RelPermalink }}">{{ .Title }}</a>
              {{ end }}
            </div>
          </li>

And this worked fine as long as I use range where .Site.RegularPages "Section" "articles"; it lists all the article files (content/articles/*.md), but now I want to have an article with images in the same directory (rather than in /static/ or /resources/), so I tried having a content/articles/some_article/_index.md - the page itself renders, but the navbar needs to be changed to .Site.RegularPagesRecursive. However, as soon as I make that change, I get this error:

execute of template failed: template: _default/articles.html:70:34: executing "_default/articles.html" at <.Site.RegularPagesRecursive>: can't evaluate field RegularPagesRecursive in type page.Site

Which seems to indicate the feature doesn’t exist yet. It was added in 0.68.0, but I get this same result both in 0.72.0 and in 0.75.1, the most recent release.

From Documentation:

.RegularPagesRecursive

Collection of all regular pages under a list page. This includes regular pages in nested sections/ list pages.


.RegularPagesRecursive without .Site,
but you cannot directly range the variables, need to run it inside {{ .Site.GetPage "/articles" }} scope.