mongodb – “Document Failed Validation” what is wrong with my schema validation

I am trying to create a collection with JsonSchema (really its “BsonSchema”) validation. This is a document that I want to insert (with bogus values). Note that Id is coming from the mongo c# driver as the ObjectID via StringObjectIdGenerator.

{
  "Id": "602ff3ed562ec58cb18c37c3",
  "UserId": 2,
  "UserName": "UserName_1",
  "Password": "Password_1",
  "PasswordSalt": "InstallSchema",
  "CreatedDateUtc": "2021-02-19T17:22:50.86151Z"
}

This is one of the many schemas that I have tried to use.

{
  "bsonType": "object",
  "properties": {
    "Id": {
      "bsonType": "objectid"
    },
    "UserId": {
      "bsonType": "int"
    },
    "UserName": {
      "bsonType": ( "string", "null" )
    },
    "Password": {
      "bsonType": ( "string", "null" )
    },
    "PasswordSalt": {
      "bsonType": ( "string", "null" )
    },
    "CreatedDateUtc": {
      "bsonType": "date"
    }
  },
  "required": ( "UserId", "UserName", "Password", "PasswordSalt", "CreatedDateUtc" )
} 

When inserting the document into the collection it reports “Document failed validation” with no more specific detail. I know the document is correct, its the schema that is not, but I cant figure out what is wrong with it. I’ve tried different variations of the Id property including _id, a string type, and removing it completely, but I dont know if thats even the problem. Any ideas on how to figure this out?

Also I did try creating the collection without schema validation and the document inserts fine. Then in Compass, I ran analysis for the collection and exported what it calls a schema (a very different format from the validator schema) and the properties and types match the schema above.