Description

When trying to query two nested ACF flexible content fields, I get this error:

{
  "errors": [
    {
      "message": "Internal server error",
      "extensions": {
        "debugMessage": "GraphQL\\Type\\Schema::getImplementations(): Return value must be of type GraphQL\\Utils\\InterfaceImplementations, null returned"
      }
    }
  ]
}

Steps to reproduce

Run a GraphQL query with two nested ACF flexible content fields:

{
  article(id: 1402, idType: DATABASE_ID) {
    pagebuilder {
      sections {
        modules {
          ... on PagebuilderSectionsModulesTabsLayout {
            tabSections {
              tabModules {
                __typename
              }
            }
          }
        }
      }
    }
  }
}

Additional context

No response

WPGraphQL Version

2.1.0

WordPress Version

6.7.2

PHP Version

8.2.0

Additional environment details

WPGraphQL for ACF 2.4.1

Please confirm that you have searched existing issues in the repo.

• Yes

Please confirm that you have disabled ALL plugins except for WPGraphQL.

• Yes
• My issue is with compatibility with a specific WordPress plugin, and I have listed all my installed plugins (and version info) above.