I've also experienced a selection created by a click at a starting point followed by shift+click at the ending point to not be copied. When pasting, the previous selection created by dragging over the desired text is still in the clipboard and is pasted instead of the new selection.
I've noticed this behavior in lxterminal and xfce-terminal.
I've also experienced a selection created by a click at a starting point followed by shift+click at the ending point to not be copied. When pasting, the previous selection created by dragging over the desired text is still in the clipboard and is pasted instead of the new selection.
I've noticed this behavior in lxterminal and xfce-terminal.