Apollo Client Cache Read Policy

Question

I have two queries like so:

const GET_GROUP_DATA = gql`
  query GetGroups {
    groups {
      id
      name
      type
      ...etc
    }
  }
`;


const GET_FORM_DATA = gql`
  query GetFormData {
    contactTypes {
      type
    }
    groups {
      id
      name
    }
  }
`;

Both are retrieving data for groups.

If I run GET_GROUP_DATA first, all the data for groups saved in my cache, however when running GET_FORM_DATA that requests contactTypes and groups, Apollo ignores the groups already in the cache and re fetches the groups along with contactTypes.

All the required fields (id and name) are present in the cache so shouldn't Apollo only send the request to fetch contactTypes?

I am assuming that I need a read policy to instruct Apollo to look in the cache first, however I have only managed to get this working with single entities like so:

readGroup: {
  read(_, { args: { groupId }, toReference }) {
    return toReference({
      __typename: "Group",
      id: groupId,
    });
  },
},

How can I set this up so that GET_FORM_DATA can make use of the cached values for group if they are available.

Not sure if its because I am requesting two different types in a single query maybe?