Spring MockMvc - Custom Validators are not registered/called in Spring Container

@Configuration
@EnableWebMvc
@ComponentScan("com.xyz.web")
class BaseTestConfig extends WebMvcConfigurerAdapter {

    @Bean
    AccountService accountService() {
        return Mockito.mock(AccountService)
    }

}

class Test {
    @Autowired WebApplicationContext wac

    MockMvc mockMvc

    @BeforeClass
    void setup() {
        mockMvc = MockMvcBuilders.webAppContextSetup(wac).build()
    }

    @Test
    void testSubmitPageFails() {
        mockMvc.perform(post("/createAccount")
                .param("account.username", "x")
                .param("confirmEmail", "y")
                .param("account.firstName", "")
                .param("account.lastName", "")
                .param("account.zip", ""))
                .andExpect(model().errorCount(5))
                .andExpect(view().name("account/createAccount"))
                .andExpect(status().isOk())
    }

    @Test
    void testSubmitPageSucceeds() {
        mockMvc.perform(post("/createAccount")
                .param("account.username", "[email protected]")
                .param("confirmEmail", "[email protected]")
                .param("account.firstName", "John")
                .param("account.lastName", "Doe")
                .param("account.zip", "22102"))
                .andExpect(flash().attributeCount(1))
                .andExpect(status().isMovedTemporarily())
                .andExpect(redirectedUrl("/home"))
    }
}

I define my test class and config class as shown above. However, controller methods having @Valid annotations not being invoked. It seems like they are not registered during Spring container initialization.

These validators registered just fine when I run the application.

Any idea why my custom validators are ignored for my controller tests?