Unable to reference Entries using PHP SDK, 422 error

I’m using the Contentful API PHP SDK library and through this API am creating a few different Entries which are going to reference each other.

I’m able to create the different entries, I’m able to edit text fields within them, both at the point of creation and after they are created, I can edit the fields. However, what I am not able to do is reference the Entries to one another.

For the purpose of this issue, the two Content Types are: ContentType-A and ContentType-B where there is a References field which can hold 0 or more References (referred to as Components).

The code that is used looks like this:

// environmentProxy handles create/update
$environment = $this->client->getEnvironmentProxy($spaceId, $environmentId);

// creating ContentType-A Entry
$entry = new Entry('ContentType-A');
$entry->setField('title', 'en-US' , $title);

// test out if I can edit the previously created entry
// call newly created entry just in case their API is cached
$newlyCreatedEntryA = $environment->getEntry($entry->getId());
$newlyCreatedEntryA->setField('title' , 'en-US' , 'Some new title');
$newlyCreatedEntryA->update();  // I can verify that the entry title changed

// create ContentType-B Entry
$entry = new Entry('ContentType-B');
$entry->setField('title', 'en-US' , 'Content Type B - ' . $title);
$newlyCreatedEntryB = $environment->getEntry($entry->getId());

// try to reference ContentType-B into Components field in ContentType-A
$newlyCreatedEntryA->setField('Components', 'en-US', $newlyCreatedEntryB);

I receive a 422 error. I’ve replaced values with the same variables as labeled above to ensure the values are correctly placed.

Client error: `PUT https://api.contentful.com/spaces/{$spaceId}/environments/{$environmentId}/entries/{$newlyCreatedEntryA->getId()}` resulted in a `422 Unprocessable Entity` response:
    "id": "InvalidEntry"
  "message": "Validation error",

Additional checks to see why it might not work:

  1. Thought it was a caching issue, so put in sleep(5) in various parts of the script to delay and allow Contentful’s systems to get updated.
  2. Verified in the application itself that the newly created contents are there
  3. Outputted values in the SDK library itself and I see the object being passed through
  4. Tried publishing both entries manually and linking them via code