Error calling Paginate

I have a weird error where most builds succeed, but then a few fail with the message:

execute of template failed: template: products/keywords.html:6:14: executing "products/keywords.html" at <.Paginate>: error calling Paginate: invoked multiple times with different arguments

I’m not sure what I’m doing wrong. How should I troubleshoot this error? I can only see .Paginate being invoked one time on products/keywords.html. I also use the same pagination partial on products/list.html. As a test, I removed pagination from products/list.html but the error persists so I assume there is no conflict between using pagination in both templates.

Content
  |-- products
        |-- _index.md
        |-- product1.md
        |-- product2.md
        |-- cars [layout = "keywords"]
             |-- _index.md

Layout/products/keywords.html

{{$related := .Paginate ((where site.RegularPages "Section" .Section).Related .)}}
{{range $related.Pages}}
  {{.Title}}
{{end}}
{{partial "pagination.html" .}}

partials/pagination.html [src]

{{ $pag := $.Paginator }}
{{ if gt $pag.TotalPages 1 }}
{{ $.Scratch.Set "dot_rendered" false }}
<nav aria-label="page navigation">
    <ul class="pagination">
        <!-- Don't show on 1st and 2nd page -->
        {{ if and (ne $pag.PageNumber 1) (ne $pag.PageNumber 2) }}
        <li class="page-item"><a href="{{ $pag.First.URL }}" rel="first" class="page-link">« First</a></li>
        {{ end }}

        {{ if $pag.HasPrev  }}
        <li class="page-item"><a href="{{ $pag.Prev.URL }}" rel="prev" class="page-link">‹ Prev</a></li>
        {{ end }}

        {{ range $pag.Pagers }}
            {{ if eq . $pag }} <!-- Current Page -->
            <li class="page-item active"><a href="{{ .URL }}" class="page-link">{{ .PageNumber }}</a></li>
            {{ else if and (ge .PageNumber (sub $pag.PageNumber 2)) (le .PageNumber (add $pag.PageNumber 2)) }}
            {{ $.Scratch.Set "dot_rendered" false }} <!-- Render prev 2 page and next 2 pages -->
            <li class="page-item"><a href="{{ .URL }}" class="page-link">{{ .PageNumber }}</a></li>
            {{ else if eq ($.Scratch.Get "dot_rendered") false }} <!-- render skip pages -->
            {{ $.Scratch.Set "dot_rendered" true }}
            <li class="page-item disabled"><a class="page-link">...</a></li>
            {{ end }}
        {{ end }}

        {{ if $pag.HasNext }}
        <li class="page-item"><a href="{{ $pag.Next.URL }}" rel="next" class="page-link">Next ›</a></li>
        {{ end }}

        <!-- Don't show on last and 2nd last page -->
        {{ if and (ne $pag.PageNumber $pag.TotalPages) ((ne $pag.PageNumber (sub $pag.TotalPages 1))) }}
        <li class="page-item"><a href="{{ $pag.Last.URL }}" rel="last" class="page-link">Last »</a></li>
        {{ end }}
    </ul>
</nav>
{{ end }}

After experimenting, I’ve been able to get rid of the error message if I don’t use Related and instead use the intersect function.

{{$keyword := .Keywords}}
{{$related := .Paginate (where (where site.RegularPages "Section" .Section) ".Keywords" "intersect" $keyword)}}
{{range $related.Pages}}
  {{.Title}}
{{end}}
{{partial "pagination.html" .}}

I would be interested in knowing why that is. Can Related not be used in this context?

The error is clear, and also impossible to debug without seeing the complete project.