Subquery element null when using a fragment

We have a query like this that works as expected:

query GetItems($getItemsInput: GetItemsInput!) {
  getItems(getItemsInput: $getItemsInput) {
    uuid
    user {
      firstName
      lastName
    }
  }
}

But when I use a fragment with the same inputs, the “user” comes back null (uuid is there both ways)

query GetItems($getItemsInput: GetItemsInput!) {
  getItems(getItemsInput: $getItemsInput) {
    ...ItemsRow
  }
}

fragment ItemsRow on Item {
  uuid
  user {
    firstName
    lastName
  }  
}

Any ideas on why and/or where we should look to figure this out? This is using the Playground as the client.

Is Item here the actual type or an interface? In the case of an interface, the playground might not be aware of a parent-child relationship between the Item interface and the actual type.

It is a type. And it also happens when using the React Apollo client

Turns out it was the result of an optimization we were doing on the backend. Worked it out.