In the PDF viewer on Zotero desktop, one can add notes (i.e., PDF comments, indicated with sticky note icons) by clicking on the "Add Note" button on the 4-button mark-up toolbar at the top of the viewer. Currently, if you click somewhere in the page, you create a note, and if you then click somewhere else on the page you create a *second* note (and so on for additional clicks). This is true whether you type something into the first note or not.

I found this surprising and slightly annoying behavior as a user, because I expected that, after creating the note and typing some text, clicking on the page would take me out of the note-typing interface and back to regular reading. I basically never need to create notes in rapid succession where needing to click the "Add Note" button each time would be burdensome. In other words, I expected that clicking the "Add Note" button would allow me to create a single note rather than putting me in a steady "Add Note mode" (until un-selecting the "Add Note" button).

I realize that there may be consistency issues with the "Highlight Text" button, since that one at least would plausibly put you in a mode you'd want to say in to highlight several pieces of text in a row.