GraphQL Argument of `6` in `posts(first: 6)` causes no post edges to be returned

[onceknown]

When running this query in the gql playground:

  query GetSeriesList($host: String!, $first: Int!) {
    publication(host: $host) {
      seriesList(first: $first) {
        edges {
          node {
            id
            name
            slug
            description {
              html
            }
            posts(first: 6) {
              edges {
                node {
                  id
                  title
                  brief
                  slug
                  publishedAt
                  coverImage {
                    url
                  }
                  author {
                    name
                    profilePicture
                  }
                }
              }
            }
          }
        }
      }
    }
  }

I get the following returned, even though there is one post in the single series in my hashnode blog:

{
  "data": {
    "publication": {
      "seriesList": {
        "edges": [
          {
            "node": {
              "id": "...",
              "name": "...",
              "slug": "...",
              "description": {
                "html": "..."
              },
              "posts": {
                "edges": []
              }
            }
          }
        ]
      }
    }
  }
}

All I need to do is choose any integer that isn't 6 to get the API to return the expected post edges:

  query GetSeriesList($host: String!, $first: Int!) {
    publication(host: $host) {
      seriesList(first: $first) {
        edges {
          node {
            id
            name
            slug
            description {
              html
            }
            posts(first: 20) {
              edges {
                node {
                  id
                  title
                  brief
                  slug
                  publishedAt
                  coverImage {
                    url
                  }
                  author {
                    name
                    profilePicture
                  }
                }
              }
            }
          }
        }
      }
    }
  }

returns:

{
  "data": {
    "publication": {
      "seriesList": {
        "edges": [
          {
            "node": {
              "id": "...",
              "name": "...",
              "slug": "...",
              "description": {
                "html": "..."
              },
              "posts": {
                "edges": [
                  {
                    "node": {
                       ...                      
                    }
                  }
                ]
              }
            }
          }
        ]
      }
    }
  }
}

Hopefully this behavior is easy to map against the resolver logic.