Why does adding customer name fields cause an internal server error in Shopify Graphql bulk operations?

Shopify Apps
1

When I run GQL in Shopify Graphql app it works fine. But in Bulk operation for customer query if I add firstName, lastName or displayName it returns internal_server_error. If I remove firstName, lastName or displayName my query works. Here is my query..

mutation {
bulkOperationRunQuery(
query: “”"
{
customers{
edges{
node{
id
email
createdAt
updatedAt
firstName
}
}
}
}
“”"
) {
bulkOperation {
id
status
}
userErrors {
field
message
}
}
}