Error creating EventBridge resources

Hello,

I am trying to create a proof-of-concept using the new eventbridge service but I am hitting issues early. I am using the following yaml configuration:

functions: 
  ProcessEvent:
    handler: xxxxx.Api.Events::xxxxx.Api.Events.EventBridgeEventProxy::ProcessEvent
    events:
      - eventBridge:
          eventBus: arn:aws:events:us-east-2:xxxxxxxxxxxxxx:event-bus/default
          pattern:
            source:
              - acme.source

I have tried a few different configurations including a non-arn event bus name and my own custom source but decided to use the example yaml to get it at least building the resources but to avail.

The one consistent error that I do receive is the following, after about 45 minutes of deployment:

Serverless Error ---------------------------------------

An error occurred: ProcessEventCustomEventBridge1 - Custom Resource failed to stabilize in expected time.

Get Support --------------------------------------------

I really want to use EventBridge but this has me hamstrung at the moment. Any insight would be welcome.

Thanks,
Ryan

For reference, here is a cf log screenshot