CloudFormation breaks on AWS::SQS::Queue with RedriveAllowPolicy property

We are specifying a RedriveAllowPolicy on our AWS::SQS::Queue in CloudFormation and are - again - receiving errors in CloudFormation without making any changes to our templates.

This happened a few weeks ago, too, so it is the second breaking change for this property we're seeing, which is unfortunate. The old thread was: https://forums.aws.amazon.com/thread.jspa?messageID=1000934&tstart=0

So, in accordance to that thread, we changed our template definition to be:

  TestQueue:
    Type: AWS::SQS::Queue
    Properties:
      VisibilityTimeout: 450
      RedriveAllowPolicy: '{"redrivePermission":"denyAll"}'
      RedrivePolicy:
        deadLetterTargetArn: !GetAtt TestDeadLetterQueue.Arn
        maxReceiveCount: 5

  TestDeadLetterQueue:
    Type: AWS::SQS::Queue
    Properties:
      MessageRetentionPeriod: 1209600

This worked for a few weeks, but now CloudFormation is throwing the following error for this exact template:

2021-12-14 10:33:14 UTC+0100 TestQueue CREATE_FAILED

Properties validation failed for resource TestQueue with message: #: extraneous key [RedriveAllowPolicy] is not permitted

Removing RedriveAllowPolicy: '{"redrivePermission":"denyAll"}' from the template solves the issue - but we want to set this policy, obviously.

I hope we're following the documentation at https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-properties-sqs-queues.html#aws-sqs-queue-redriveallowpolicy precisely.

Any help appreciated. This is quite a big blocker in our process right now.

Full template file to reproduce the error:

AWSTemplateFormatVersion: '2010-09-09'
Description: A prototype stack to test out CloudFormation definitions.
Metadata: {}
Transform: AWS::Serverless-2016-10-31

Resources:

  TestQueue:
    Type: AWS::SQS::Queue
    Properties:
      VisibilityTimeout: 450
      RedriveAllowPolicy: '{"redrivePermission":"denyAll"}'
      RedrivePolicy:
        deadLetterTargetArn: !GetAtt TestDeadLetterQueue.Arn
        maxReceiveCount: 5

  TestDeadLetterQueue:
    Type: AWS::SQS::Queue
    Properties:
      MessageRetentionPeriod: 1209600