Why does another text element appear when copying text?

Question

Adobe Illustrator

CS6

when duplicating a text element with the mouse and the Alt key, the program inserts a new element with the same content

, that is, after successful duplication, the selection from the new duplicate element is removed, the program inserts another extra new element on the page,

that is, with such copying, two duplicates appear instead of one

and such a glitch was on cs2 or 3