Having a bean class with @ApplicationScoped, which has a @PostConstruct and is implementing the following Interface:

@Path("/validated")
public interface ValidatedJaxRsInterface {
    
    @GET
    @Valid
    @Produces(MediaType.APPLICATION_JSON)
    GreetingModel getHelloGreeting();
}

will result in calling the getHelloGreeting method of the implementation class before the @PostConstruct is getting executed.

This can be reproduced with the attached reproducer application...

NOTE: There is a side-issue that the getHelloGreeting is called twice. As per discussion on WFLY-11987 this is not in scope of this fix.