Medley now comes with a new modernization feature that improves text editing: the arrow keys move the cursor as expected in TEdit, Execs, and most editing fields (but not SEdit). Here the cursor moves under arrow key control in TEdit.
In classic Medley the cursor was moved with the mouse and TEdit had some keyboard support for cursor movement but not via the arrow keys.
Download medley-250224-3aa58b63 or later. Cursor keys currently don't work on Medley Online.