Cognito Error decoding token headers.

Hello,
The repo. https://aws.amazon.com/blogs/security/building-fine-grained-authorization-using-amazon-cognito-api-gateway-and-iam/
which is a basic Cognito setup works well on my own AWS account. But on another officlal account I see a problem.

Since the repo. is the same and we execute it in the same way I am wondering if it has anything to do with the token itself. Shouldn't it be the same token ? We don't modify the cloudformation template at all.

Thanks

Edited by: Mohan Radhakrishnan on Jul 20, 2021 6:01 PM