I tapped the unanswered link, and the first one on the list said it had one answer. That answer was seven days old, so it couldn't be a page refresh problem.
I'm guessing that in one place the meaning is "no accepted answers" and in the other place "no attempted answers".
The Unanswered tab will show questions with no upvoted answers, so even if the question has 10 answers it will show here as long as no answer is upvoted.
If you want to show the questions with no answer at all, click on the "no answers" sub-tab below (marked with yellow in the image).
Note the the ones that already have answers may be because they're poor answers. For example, if someone answers a question with a wrong answer and gets downvoted, they won't appear in the 'no answers' list, but they will still appear in the unanswered questions, until they get an answer with positive votes.
Therefore it's still worth looking at this list - if a question has a good answer but with 0 points, give it an upvote, and if not, see if you can answer it :)
