Incorrect code coverage when switch with enum is involved

I always use "Run SomeTest with Code Coverage" and noticed today some weird results when the source code uses a switch statement with an enum.

The class to test:

public class Calculator {
    public int calc(int op, int i1, int i2) {
        switch (op) {
            case 0:
                return i1 * i2;
            default:
                throw new UnsupportedOperationException("Unknown operation " + op);
        }
    }
}

And the test class:

public class CalculatorTest {

    private final Calculator calculator = new Calculator();
    private final int i1 = 5;
    private final int i2 = 7;

    @Test
    public void calc0() {
        assertThat(calculator.calc(0, i1, i2)).isEqualTo(35);
    }

    @Test
    public void calc1() {
        assertThatThrownBy(() -> calculator.calc(1, i1, i2))
            .isInstanceOf(UnsupportedOperationException.class);
    }

}

If I run this class with code coverage, I get the expected result:

Now let's change Calculator class using an Operation enum:

public enum Operation {
    ADD, SUBTRACT, MULTIPLY, DIVIDE
}

public class Calculator {
    public int calc(Operation op, int i1, int i2) {
        switch (op) {
            case MULTIPLY:
                return i1 * i2;
            default:
                throw new UnsupportedOperationException("Unknown operation " + op);
        }
    }
}

And the updated test class:

public class CalculatorTest {

    private final Calculator calculator = new Calculator();
    private final int i1 = 5;
    private final int i2 = 7;

    @Test
    public void calc0() {
        assertThat(calculator.calc(Operation.MULTIPLY, i1, i2)).isEqualTo(35);
    }

    @Test
    public void calc1() {
        assertThatThrownBy(() -> calculator.calc(Operation.ADD, i1, i2))
            .isInstanceOf(UnsupportedOperationException.class);
    }

}

But if I now run the test class, the test coverage report shows some strange results:

I tried both JaCoCo as IntelliJ code coverage runners with the same result.