Dragging over a note on Dashboard no longer selects its text, so a click that moves slightly still opens the note. To copy a note, right-click it, or press and hold it on a phone or tablet, and choose Copy text, which copies the whole note. To copy part of a note, open it and select the text there.
Notes on Dashboard open on any click again
A click anywhere on a note on Dashboard opens it again. Copy text in the note's menu copies the whole note.