hop of those help? I think ConstraintViolationException is not occurred because during update Hibernate don't flush result to database on the spot. Try to replace in your test save() with saveAndFlush().
fixed the issue. Will look into that further I found the solution. Instead of declare the Errors in the method (it came with the Bean A asociated by the target field) I create a new one before the validation call. Something like:
BindingResult errors = new BeanPropertyBindingResult(beanB,"BeanB");
Validate Spring Bean different fields different times
Any of those help According to this you should add .cors().and() in your configure() method as well. There are also other possible solutions, for example by setting the CORS-configuration specific to each endpoint as seen here.