Extremely slow GraphQL performance even with very simple query and schema

I am trying to switch over from REST to GraphQL, and am experiencing horribly slow responses for queries. As in 5000-7000+ ms for a super simple, small request. I’ve spent days on this, tried everything, and am about to give up. Any help would be greatly appreciated.

I have greatly reduced the schema from the huge one auto-generated to a tiny one for testing (no difference), implemented filters (no difference), simplified the query to only return a few, have indexed the main field (helped a tiny bit), and have not resolvers or anything special at all.

I am on the M10 tier.

The schema:

{
  "title": "mlbgame",
  "properties": {
    "_id": {
      "bsonType": "string"
    },
    "_simulation": {
      "bsonType": "bool"
    },
    "date": {
      "bsonType": "string"
    },
    "endDate": {
      "bsonType": "date"
    },
    "gameInfo": {
      "bsonType": "string"
    },
    "gameStatus": {
      "bsonType": "string"
    },
    "id": {
      "bsonType": "string"
    },
    "minutesRemaining": {
      "bsonType": "int"
    },
    "percentComplete": {
      "bsonType": "double"
    },
    "sport": {
      "bsonType": "string"
    },
    "startDate": {
      "bsonType": "date"
    },
    "status": {
      "bsonType": "string"
    }
  }
}

The query:

query GamesForCalendar($dateFrom: DateTime!, $dateTo: DateTime!) {
    mlbgames(query: {startDate_gte: $dateFrom, startDate_lte: $dateTo}) {
      id
      status
      sport
      date
      startDate
      endDate
      gameInfo
      gameStatus
      minutesRemaining
      percentComplete
      _simulation
    }
  }

A sample log entry:

Function Call Location:
US-OR
GraphQL Query:
query GamesForCalendar($dateFrom: DateTime!, $dateTo: DateTime!) { mlbgames(query: {startDate_gte: $dateFrom, startDate_lte: $dateTo}) { id status sport date startDate endDate gameInfo gameStatus minutesRemaining percentComplete _simulation __typename } }
Compute Used:
18736722090 bytes•ms
Remote IP Address:
136.32.230.69
Rule Performance Metrics:
{
  "dfsdb.mlbgames": {
    "roles": {
      "default": {
        "matching_documents": 19,
        "evaluated_fields": 0,
        "discarded_fields": 0
      }
    },
    "no_matching_role": 0
  }
}

I have an index on startDate as well. The result set is only 6k. Please help! Surely I am missing something, or there is some explanation, as this is completely unusable.

Best,
Greg