Kafka Connect Deserialized object without properties

[adrien-brunelat-sb]

Hello there, I'm trying to deserialize this event with a Glue schema through Kafka Connect:

{
  "EventName": "test_name",
  "ClientTimestamp": "2023-11-08T17:19:40.317Z",
  "Payload": {
    "IsSuccessful": "true",
    "LoginDuration": "1.950996",
    "LoginType": "XSX",
    "SecondsSinceLaunch": "33.477",
    "SessionID": "EF2E41A645707B10A11973B1378861D4",
    "UserEmailAddress": "[email protected]",
    "UserID": "3560342d4ca25c99a8f92562575acc27"
  },
  "EventTimestamp": "2023-11-08T17:19:40.317Z"
}

This is my schema definition:

{
	"$id": "https://example.com/schema.json",
	"$schema": "http://json-schema.org/draft-07/schema#",
	"title": "AnalyticsEvent",
	"type": "object",
	"properties": {
		"EventName": {
			"type": "string",
			"description": "EventName"
		},
		"EventTimestamp": {
			"type": "string",
			"description": "EventTimestamp"
		},
		"ClientTimestamp": {
			"type": "string",
			"description": "ClientTimestamp"
		},
		"Payload": {
			"type": "object",
			"description": "Payload"
		}
	}
}

Then Kafka Connect sends everything to Snowflake via a Snowpipe. I've left Payload without properties because they can vary and I want it to be deserialized as a Snowflake semi-structured "variant" column. Unfortunately, on Snowflake's side, the payload column is always {}, meaning empty object, all other fields are ok.

Would this be coming from the deserializer? How could I fix this?