Can't create a new lambda function from a step function - aws-lambda

Question

I'm trying to create a step function in AWS that creates a lambda function, although getting the following error whenever I try to run it:
"Could not unzip uploaded file. Please check your file, then try to upload again."
I tried uploading the ZIP file to a lambda directly via the console, it uploads it without any issue, and confirmed in my network tab that the ZIP file encoding matches what I'm sending via the step function.
Step function definition:
{
"Comment": "Create lambda",
"StartAt": "Create Lambda",
"States": {
"Create Lambda": {
"Type": "Task",
"Parameters": {
"Code": {
"ZipFile.$": "$.file"
},
"FunctionName.$": "$.name",
"Role": "<<redacted>>",
"Handler.$": "$.handler",
"Runtime": "python3.7"
},
"Resource": "arn:aws:states:::aws-sdk:lambda:createFunction",
"ResultPath": null,
"End": true
}
}
}
Event I'm executing the step function with:
{
"file": "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",
"name": "test-lambda",
"handler": "handler.handler",
}