When you click the "No Answers" tab, that is the one that has questions with literally no answers. The rest of the "Unanswered" tabs are really lists of questions without accepted answers. Plenty of questions on that list with answers... but no checkmarks.

When you click the "No Answers" tab, that is the one that has questions with literally no answers.

The rest of the "Unanswered" view tabs are really lists of questions with answers that have no upvotes or have not been accepted.

There are plenty of questions on that list with answers, but as they have no upvotes it means other users did not think it worked or solved the issue, leaving the question still unanswered.