What Debezium connector do you use and what version?

v2.2.1.Final (custom)

What is the connector configuration?

"collection.include.list":"Test.Test_Collection",
"connector.class":"io.debezium.connector.mongodb.MongoDbConnector",
"errors.log.enable":"true",
"errors.log.include.messages":"true",
"field.name.adjustment.mode":"avro",
"key.converter":"org.apache.kafka.connect.json.JsonConverter",
"mongodb.connection.string":"mongodb+srv://********:****************@************.*******.mongodb.net",
"mongodb.ssl.enabled":"true",
"name":"mongo",
"signal.data.collection":"Test.testCollection",
"topic.prefix":"mongo",
"transforms":"ExtractNewDocumentState",
"transforms.ExtractNewDocumentState.type":"io.debezium.connector.mongodb.transforms.ExtractNewDocumentState"
"value.converter": "org.apache.kafka.connect.json.JsonConverter"

What is the captured database version and mode of deployment?

(E.g. on-premises, with a specific cloud provider, etc.)

N/A

What behaviour do you expect?

Column names that don't adhere to Avro naming standards to be sanitized e.g. "bad.column-name" becomes "bad_column_name"

What behaviour do you see?

No sanitization.

But it's clear from the ExtractNewDocumentStateTestIT that actually field.name.adjustment.mode is considered a Transformation configuration property and not a common Connector configuration property as the documentation suggests.

If you define the property under the ExtractNewDocumentState configuration e.g. "transform.ExtractNewDocumentState.field.name.adjustment.mode":"avro" then it will sanitize the field names.

Do you see the same behaviour using the latest relesead Debezium version?

(Ideally, also verify with latest Alpha/Beta/CR version)

Yes