Custom taxonomies not returning correct data

[seagyn]

When making a query to a custom taxonomy, I am getting inconsistent results. 1 taxonomy will return terms from another and sometimes it errors with: Method WPGraphQL\\Data\\Loader\\TermObjectLoader::loadKeys is expected to return an array with keys but got: null

Some example queries:

This returns terms from another custom tax

query GetCarMakes($first: Int, $after: String) {
    carMakes(first: $first, after: $after) {
      edges {
        node {
          id
          name
            carMakeId
        }
      }
    }
  }

This errors:

query GetCarModels($first: Int, $after: String) {
    carModels(first: $first, after: $after) {
      edges {
        node {
          id
          name
            carModelId
        }
      }
    }
  }

This is how I registered the tax (the other is identical):

register_taxonomy(
        'car_make',
        [ 'car', 'fixxrs' ],
        [
            'label'               => __( 'Make', 'fixxr-features' ),
            'public'              => false,
            'show_ui'             => true,
            'show_in_graphql'     => true,
            'graphql_single_name' => 'CarMake',
            'graphql_plural_name' => 'CarMakes',
            'hierarchical'        => true,
        ]
    );