When a single file is open on multiple tabs/windows or in a split pane, if on a window "undo" is performed, every other window move its position centering on the last "undo" modification.

E.g.: main.c is open, window is split. On the right pane cursor is at line 400, on the left one at line 900. If you undo something on the right pane, line 405 let's say, the left one move back on line 405. So now both panes point on the same line.