When the cursor is located at the beginning of a line within a nested itemize environment and then moved with up/down arrow keys, the cursor does not stay at the very beginning of each line. Instead it often moves to the first non-space character, e.g., the beginning of \item, and sometimes it goes other positions. There is no clear patterns where the cursor would go.
The same problem occurs when SHIFT is pressed to select text. As a result, I cannot select, say, exactly a few lines of text without including the leading spaces of the line after the selected area.
Moving the cursor up and down from the middle of a line seems okay.