Adjusting encryption settings for s3 upload?

[crackernutter]

I am getting an error when converting my slpk and uploading to S3. The message is
"code" : "IDS_I3S_IO_WRITE_FAILED", "message" : "Error : Failed to write to File SLPK://nodes\\47\\textures\\0_0_1"

Unclear what could be causing this, since my machine has appropriate IAM roles to upload to S3, which I've successfully done on the same machine using boto3.

However, using boto3, I do have to specify ServerSideEncryption to AES256. The operations will fail if I don't specify this.

For example:
client.put_object(Bucket=bucketname, Key=foldername, ServerSideEncryption='AES256')
and
client.upload_file(file, Bucket=bucketname, Key=f"samplepublish/sampleslpk.slpk", ExtraArgs={"ServerSideEncryption":'AES256'})

I'm curious if there is a way to pass in this to the converter, or more generally if its possible that this failure is because I can't specify this extra parameter.