Take any editing text box, like the one that comes up when you want to rename a file in a torrent.

On Windows 10 at least, when I move the mouse to the text box it remains an arrow cursor, and left single/double-clicking does nothing at all!

However if I move the cursor vertically near the top part of the text box, it changes to an I-shaped edit cursor as expected, and left single/double-clicking behaves as expected.

Basically, the "mouse edit detection area" (don't know how else to put it) is wrongly shifted up in any text box, such that the mouse cursor changes to an edit cursor only near the top part.