Strange java enum bug

for(Answer ans : assessmentResult.getAnswersAsList()) { //originally stored in a table
    //AnswerStatus stat = ans.getStatus();
    if (ans.getStatus() == AnswerStatus.NOT_ASSESSED) {
        assessed = false;
    }
}

...
if (AnswerStatus.NOT_ASSESSED == ans.getStatus())
...

if (AnswerStatus.NOT_ASSESSED.equals(ans.getStatus()))

if (ans.getStatus().equals(AnswerStatus.NOT_ASSESSED))