Unit testing logs using streams working just for the first test

I have a JUnit test class, which uses Mockito, in which I need to test if something is being logged correctly. It basically looks something like:

public class MyTest {

    private final PrintStream outDefault = System.out;
    private final PrintStream errDefault = System.err;

    private final ByteArrayOutputStream outContent = new ByteArrayOutputSteam();
    private final ByteArrayOutputStream errContent = new ByteArrayOutputStream();

    @Before
    public void setUp() {
        System.setOut(new PrintStream(outContent));
        System.setErr(new PrintStream(errContent));  
    }

    @After
    public void takingDown() {
        System.setOut(outDefault);
        System.setErr(errDefault);
    }

    @Test
    public Test1_Condition_Expected() {
        assertTrue(errContent.toString().toLowerCase().contains("...")):
    }

    ...

    @Test
    public TestN_Condition_Expected() {
        assertTrue(errContent.toString().toLowerCase().contains("...")):
    }
}

I have also tried to do a flush and close of the streams in the @After, but it does not seem to work neither:

@After
public void takingDown() {
    try {
        outContent.flush();
        errContent.flush();
        outContent.close();
        errContent.close();
    } catch (IOException e) {
        e.printStackTrace();
    }

    System.setOut(outDefault);
    System.setErr(errDefault);
}

When I run the whole class, the first tests passes but the rest don't. If I run the tests one by one then all of them passes.

I have debugged the code and everything seems to work properly, but for tests other than the first one the streams are not getting the logs, so obviously they fail.