appsync schema @aws_iam , @aws_api_key disappeared with Amplify, Amazon opensearch service

At some point, appsync failed to query, so when I looked for the cause, @aws_iam and @aws_api_key disappeared from the appsync schema.

It suddenly disappeared, I don't know why.

------before--------

type User @aws_iam
@aws_api_key {
	id: ID!
}

------after--------

type User  {
	id: ID!
}

The service was a production service and it almost got into trouble.

Until the current searchable data

I managed to fix it this way, but I don't know why this happened.

python3 ddb_to_es.py \
  --rn 'us-west-2' \ # Use the region in which your table and OpenSearch domain reside
  --tn 'Post-XXXX-dev' \# Table name
  --lf 'arn:aws:lambda:us-west-2:<...>:function:amplify-<...>-OpenSearchStreamingLambd-<...>' \ # Lambda function ARN, find the DynamoDB to OpenSearch streaming functions, copy entire ARN
  --esarn 'arn:aws:dynamodb:us-west-2:<...>:table/Post-<...>/stream/2019-20-03T00:00:00.350' # Event source ARN, copy the full DynamoDB table ARN

Is it because the capacity of Amazon opensearch service is t2.small.search?

I don't know the answer because I'm only guessing. Similar Cases and Causes

please.