In this case, a class A extends another class B that implements an interface X with constraints. At the same time, A implements another interface Y that has the same methods of X but no constraints. Validator works differently according to the order that gets hierarchy metadata.

And depending on which interface gets processed, the result differs. Sounds like a theory. We will need to look closer at the code and try to re-produce it. Not sure yet what the right path is in this case.

Or recognize enhanced classes and exclude them

So far we try to stay away from any code which tries to detect and handle enhanced classes specifically. Bean Validation is (or should be) agnostic to this.