Issues Creating MediaConnect Flows with Cloudformation Template

Hi,

I'm struggling creating Media Connect flows using cloudformation where the ingest protocol is not zixi-push. The documentation does state that srt-listener is not supported via cloudformation ( reference https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-resource-mediaconnect-flowsource.html#cfn-mediaconnect-flowsource-maxlatency ) but I'm trying "rtp" and it fails.

Additionally, the error message is not very helpful "Error occurred during operation 'AWS::MediaConnect::Flow'." (RequestToken: <redacted>, HandlerErrorCode: GeneralServiceException)"

A working template (using Zixi on port 2088) looks like this;

`{
    "AWSTemplateFormatVersion": "2010-09-09",
    "Description": "Media Connect Flow Test",
    "Resources": {
        "MediaConnectFlowA": {
            "Type": "AWS::MediaConnect::Flow",
            "Properties": {
                "Name": "WIZARDA",
                "AvailabilityZone": "eu-west-1b",
                "Source": {
                    "Name": "WIZARDASource",
                    "StreamId": "A",
                    "Description": "Media Connect Flow Test - WIZARDA",
                    "Protocol": "zixi-push",
                    "IngestPort": 2088,
                    "WhitelistCidr": "<redacted>/32"
                }
            }
        }
    }
}`

but keeping the protocol as zixi and changing the ingress port results in failure (this could be be design I guess as it's a non-standard Zixi port).

Similarly, and more importantly for what I want to do, trying to change the protocol to "rtp" fails e.g.

{
    "AWSTemplateFormatVersion": "2010-09-09",
    "Description": "Media Connect Flow Test",
    "Resources": {
        "MediaConnectFlowA": {
            "Type": "AWS::MediaConnect::Flow",
            "Properties": {
                "Name": "WIZARDA",
                "AvailabilityZone": "eu-west-1b",
                "Source": {
                    "Name": "WIZARDASource",
                    "StreamId": "A",
                    "Description": "Media Connect Flow Test - WIZARDA",
                    "Protocol": "rtp",
                    "IngestPort": 2088,
                    "WhitelistCidr": "<redacted>/32"
                }
            }
        }
    }
}

Can anyone advise on the right construct to create a flow with RTP source? (also rtp-fec failed)

for completeness, the I've run via the console and also using the CLI e.g.

aws --profile=aws-course  --region=eu-west-1 cloudformation create-stack --stack-name="mediaconnect-rtp" --template-body file://..\MConly.json