8 – D8 How to migrate relationships from json_api source

I’m trying to merge content from two D8 sites, using the migration api and json_api as a source. There are terms that have been migrated so I’m trying to migrate the relationships

Source data looks like:

field_topics    
  data   
    0   
        type    "taxonomy_term--taxonomy_topics"
          id    "ab6ea190-3f59-4eab-a756-621e868d9f14" 

process
  field_topics:
    plugin: sub_process
    source: field_topics
    process:
      target_id:
        plugin: entity_lookup
        entity_type: taxonomy_term
        source: id
        access_check: false
        value_key: uuid
        bundle_key: vid
        bundle: topic
        ignore_case: true

This returns data in the following format:

"field_topics" => array:1 [
    0 => array:1 [
      "target_id" => "32"
    ]
  ]

But this relationship does not actually show-up when editing the node.

If anyone has an example of how to accomplish this it would be appreciated.

Thanks.