Amazon Cognito integration with Spring Boot for restricting endpoint access

Any chance Amazon people would be able to provide such example as well?

I personally tried to follow Quick Start Guide directly present in Cognito app, but for some reason (entirely possible, that my setup is at fault) after authentication, app starts to loop, when I am trying to access thymeleaf page, that initially triggered authentication process.

Would be very useful to have an example of how it should be.