Whenever a new window is created - by, perhaps, spitting a tab group - the new window is horizontally scrolled so the end of a line is positioned in the center of the window. Most times this results in just a few characters on the left of the window and a complete lack of reference as to what you're looking at.
SE never used to do this when splitting or creating a window. I think the proper action should be to position the left-most colulm of the document at the left-most column of the window. Optionally, if that leaves the cursor off to the right, the window could be scrolled until the cursor comes into view.
