I love the recent feature of editing PDFs with comments/sticky notes. However, clicking the "Comments" button on the top-right of the screen to show all the comments in the document in the right margins appears to prevent adding more comments until it is turned back off. Specifically, once the Comments button is selected, text cannot be selected/highlighted by dragging the mouse over it.
Once the comments are shown, I'd love to add comments while looking at existing ones!