undefined as first line in template created by cdk synth

[emcfins]

I'm trying to synthesize my cloudformation templates and am running into an issue with the templates.

Every time I run the command, the first line in my template file is undefined. What would be causing this? Debug isn't showing anything.

Command is:
cdk synth -vvvv --debug --asset-metadata false --path-metadata false -j true Local/AppStack > cloudformation.template

Output snippet:

undefined
{
  "Resources": {
    "CoreAccessLogsBucket9CCDFB3E": {
      "Type": "AWS::S3::Bucket",
      "Properties": {
        "AccessControl": "LogDeliveryWrite",
        "BucketEncryption": {
          "ServerSideEncryptionConfiguration": [
            {
              "ServerSideEncryptionByDefault": {
                "SSEAlgorithm": "AES256"
              }
            }
          ]
        },

I'm struggling to figure out what would be printed into my template before the resources.
I'm unsure of what other information I could provide to help nail down what I may be doing wrong.

Any help would be greatly appreciated.
Thank you.