Unable to launch App Runner Service using AWS CDK (InternalFailure)

We have been trying to launch App Runner Service using CDK (Java) but keep getting the following error.

Resource handler returned message: "null" (RequestToken: 565eeb6a-8af1-af59-5612-12ef28c1380e, HandlerErrorCode: InternalFailure)

To provide details, our CDK code does the following:

1. Creates an AWS Code Pipeline for building our code (CDK + Spring Boot Service) from GitHub
2. Builds a Docker image for a Spring Boot Service.
3. Upload the Docker image to AWS ECR.
4. Launch AWS App Runner --> This step fails

We were able to comment out step 4 in our CDK code and then manually launch AWS App runner from console using the Docker image built in Step 3. This makes us believe that something is wrong with either our CDK code or AWS Cloud Formation which runs the CDK.

Thank you for looking at our issue.