Describe the bug
Started from scratch and deployed the solution to "us-west-2" region.
After running a test in another region created using the "Regional Deployment CloudFormation Template URL", the console UI says the test failed to parse results.

To Reproduce

1. Deploy the Distributed Load Testing to "us-west-2" using template URL https://s3.amazonaws.com/solutions-reference/distributed-load-testing-on-aws/latest/distributed-load-testing-on-aws.template.
2. Use the Regional Deployment CloudFormation Template URL to deploy the solution to a different region (ap-southeast-2): https://s3.us-west-2.amazonaws.com/{stack-name}-dlttestrunnerstoragedltscenariosbuc-1m7mtd4m3szgj/regional-template/distributed-load-testing-on-aws-regional.template
3. Run a test in the second region.

Expected behavior

User should see test results and metrics for the completed test on the console UI.

Please complete the following information about the solution:

• Version: [e.g. v1.1.0] 3.2.3
• Region: [e.g. us-east-1] us-west-2, ap-southeast-2, eu-west-1
• Was the solution modified from the version published on this repository? No
• If the answer to the previous question was yes, are the changes available on GitHub?
• Have you checked your service quotas for the services this solution uses? No
• Were there any errors in the CloudWatch Logs? Yes, see screenshots below.

Screenshots

First ran a test in the region the solution was initially deployed to (us-west-2), and I was able to view the results as expected.

When I ran a test in a different region (ap-southeast-2 or eu-west-1), the test fails to show the results.

In the CloudWatch log group /aws/lambda/{stack-name}-DLTLambdaFunctionResultsParserFF5CC9-OQEageflKRLm, I can see error logs

Additional context

I tried deleting and deploying the entire CloudFormation stack twice but behaviour is the same.
I used to heavily use version 3.2.0 before upgrading the stack.
During test run, I can see the real-time results for all regions under test, so I know traffic is being sent and metrics collected as expected.