Open the Lectora .AWT file in a text editor. Find the NOTE tag, inside it find the NOTEPOS tag, inside it you will see the X and Y position of the note handle, which you can edit to e.g. 100 and 100 pixels. See attached screenshot.
If you don’t want to edit the .awt file you can also zoom out to 25% then select another page and when you come back to the page with the note you’ll see the icon off the page. Drag it onto the page and open.