The tool for labeling the bivariate chloropleth legend appears to be reversed. That is...if the key says I am editing the right label it will actually be the left label, if it says I am editing the top label it will actually be the bottom and vice versa. A bit confusing but manageable with the legend pane that shows at the same time. Just FYI for improving the project, appreciate the bivariate tool, it is great!
I couldnt reproduce this could you share your map?