Accuracy logistic regression classification

How does the Classification learner toolbox compute the accuracy when using the logistic regression method? The screenshot attached shows an example where the displayed accuracy (66.7%) does not coincide with the accuracy calculated from the confusion plot (20/26*100=76.9%).

[John D'Errico]

Please don't post multiple questions on the same topic. If you want to add information, then just attach it to your current question, either by editing the question, or by adding a comment.