Why just one test worked when using mockStatic in method modified by @BeforeClass?

[luoyanzecs]

Why test1 logger the message, but I use mockStatic in @BeforeClass?
How to make test1's logger mock just using mockStatic.
junit:4.13
Test Class

@RunWith(PowerMockRunner.class)
@PrepareForTest({
        LoggerFactory.class
})
public class ServiceTest {

    @InjectMocks
    private ServiceB serviceB;

    @BeforeClass
    public static void setUpClass() {
        PowerMockito.mockStatic(LoggerFactory.class);
        PowerMockito.when(LoggerFactory.getLogger(Mockito.any(Class.class)))
                .thenReturn(PowerMockito.mock(Logger.class));
    }

    @Test
    public void test() {
        String s = serviceB.fun1();
    }

    @Test
    public void test1() {
        String s = serviceB.fun1();
    }
}

ServiceB

@Service
public class ServiceB {

    private final Logger logger = LoggerFactory.getLogger(ServiceB.class);

    @Autowired
    private ServiceA serviceA;

    public String fun1() {
        logger.info("------serviceB--log------");
        return "Hello";
    }
}

console log

23:07:53.213 [main] INFO com.example.surefiletest.service.ServiceB - ------serviceB--log------

Process finished with exit code 0