Connected board column via api

I can’t seem to retrieve the values of connect board column.
Use this query:

query($itemId: [ID!]) {
items(ids: $itemId) {
column_values {
id
text
value
type
… on BoardRelationValue {
display_value
linked_item_ids
linked_items {
id
name
}
}
column {
id
title
}
}
}
}

Response is always:
Contacts: { id: ‘board_relation_mkq18fb2’,
text: null,
value: null,
type: ‘board_relation’
}

  • the column is not blank.
  • there are permissions.