AppSync RDS HTTP 500 Errors

This morning we started getting intermittent "500 Internal Server Error" responses from appsync with message "RDSHttp:{}".

We do not seem to get the error on any standard query, but including 1 sub resolver we get the errors 50% of the time, 2 sub resolvers 90 %, and 3 sub resolvers 100% of the time. Using queries that return basically no data is the same issue. This is not query specific, any query that uses a sub resolver schema wide currently has this issue.

Is some major issue going on currently? This has brought our stack to its knees. Issuing the exact same queries directly to the data api out of AppSync runs without issue.

PLEASE HELP

Using CloudTrail we see the following:

{
"eventVersion": "1.05",
"userIdentity": {
"type": "AssumedRole",
"principalId": "xxxxx",
"arn": "xxxxxx",
"accountId": "xxxxx",
"accessKeyId": "xxxxx",
"sessionContext": {
"sessionIssuer": {
"type": "Role",
"principalId": "xxxxxx",
"arn": "xxxxxx",
"accountId": "xxxxxxx",
"userName": "xxxxxx"
},
"webIdFederationData": {},
"attributes": {
"mfaAuthenticated": "false",
"creationDate": "2020-11-18T14:02:44Z"
}
},
"invokedBy": "appsync.amazonaws.com"
},
"eventTime": "2020-11-18T14:02:44Z",
"eventSource": "rdsdata.amazonaws.com",
"eventName": "ExecuteStatement",
"awsRegion": "us-east-2",
"sourceIPAddress": "appsync.amazonaws.com",
"userAgent": "appsync.amazonaws.com",
"errorCode": "InternalServerErrorException",
"requestParameters": {
"continueAfterTimeout": false,
"database": "**",
"includeResultMetadata": true,
"parameters": [],
"resourceArn": "xxxxxx",
"schema": "**",
"secretArn": "xxxxxx",
"sql": "**"
},
"responseElements": null,
"requestID": "9d4266dc-06b3-4eec-940c-540cdaf1cca4",
"eventID": "fe8ad37a-db83-4e6d-8793-53f08d29e61f",
"eventType": "AwsApiCall",
"recipientAccountId": "xxxxxx"
}